Add m-esr52 at 52.6.0

32 files changed, 6164 insertions, 0 deletions

diff --git a/dom/media/eme/CDMCaps.cpp b/dom/media/eme/CDMCaps.cpp
new file mode 100644
index 0000000000..20ff63bad5
--- /dev/null
+++ b/dom/media/eme/CDMCaps.cpp
@@ -0,0 +1,170 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/CDMCaps.h"
+#include "mozilla/EMEUtils.h"
+#include "nsThreadUtils.h"
+#include "SamplesWaitingForKey.h"
+
+namespace mozilla {
+
+CDMCaps::CDMCaps()
+  : mMonitor("CDMCaps")
+{
+}
+
+CDMCaps::~CDMCaps()
+{
+}
+
+void
+CDMCaps::Lock()
+{
+  mMonitor.Lock();
+}
+
+void
+CDMCaps::Unlock()
+{
+  mMonitor.Unlock();
+}
+
+CDMCaps::AutoLock::AutoLock(CDMCaps& aInstance)
+  : mData(aInstance)
+{
+  mData.Lock();
+}
+
+CDMCaps::AutoLock::~AutoLock()
+{
+  mData.Unlock();
+}
+
+// Keys with MediaKeyStatus::Usable, MediaKeyStatus::Output_downscaled,
+// or MediaKeyStatus::Output_restricted status can be used by the CDM
+// to decrypt or decrypt-and-decode samples.
+static bool
+IsUsableStatus(dom::MediaKeyStatus aStatus)
+{
+  return aStatus == dom::MediaKeyStatus::Usable ||
+         aStatus == dom::MediaKeyStatus::Output_restricted ||
+         aStatus == dom::MediaKeyStatus::Output_downscaled;
+}
+
+bool
+CDMCaps::AutoLock::IsKeyUsable(const CencKeyId& aKeyId)
+{
+  mData.mMonitor.AssertCurrentThreadOwns();
+  for (const KeyStatus& keyStatus : mData.mKeyStatuses) {
+    if (keyStatus.mId == aKeyId) {
+      return IsUsableStatus(keyStatus.mStatus);
+    }
+  }
+  return false;
+}
+
+bool
+CDMCaps::AutoLock::SetKeyStatus(const CencKeyId& aKeyId,
+                                const nsString& aSessionId,
+                                const dom::Optional<dom::MediaKeyStatus>& aStatus)
+{
+  mData.mMonitor.AssertCurrentThreadOwns();
+
+  if (!aStatus.WasPassed()) {
+    // Called from ForgetKeyStatus.
+    // Return true if the element is found to notify key changes.
+    return mData.mKeyStatuses.RemoveElement(KeyStatus(aKeyId,
+                                                      aSessionId,
+                                                      dom::MediaKeyStatus::Internal_error));
+  }
+
+  KeyStatus key(aKeyId, aSessionId, aStatus.Value());
+  auto index = mData.mKeyStatuses.IndexOf(key);
+  if (index != mData.mKeyStatuses.NoIndex) {
+    if (mData.mKeyStatuses[index].mStatus == aStatus.Value()) {
+      // No change.
+      return false;
+    }
+    auto oldStatus = mData.mKeyStatuses[index].mStatus;
+    mData.mKeyStatuses[index].mStatus = aStatus.Value();
+    // The old key status was one for which we can decrypt media. We don't
+    // need to do the "notify usable" step below, as it should be impossible
+    // for us to have anything waiting on this key to become usable, since it
+    // was already usable.
+    if (IsUsableStatus(oldStatus)) {
+      return true;
+    }
+  } else {
+    mData.mKeyStatuses.AppendElement(key);
+  }
+
+  // Only call NotifyUsable() for a key when we are going from non-usable
+  // to usable state.
+  if (!IsUsableStatus(aStatus.Value())) {
+    return true;
+  }
+
+  auto& waiters = mData.mWaitForKeys;
+  size_t i = 0;
+  while (i < waiters.Length()) {
+    auto& w = waiters[i];
+    if (w.mKeyId == aKeyId) {
+      w.mListener->NotifyUsable(aKeyId);
+      waiters.RemoveElementAt(i);
+    } else {
+      i++;
+    }
+  }
+  return true;
+}
+
+void
+CDMCaps::AutoLock::NotifyWhenKeyIdUsable(const CencKeyId& aKey,
+                                         SamplesWaitingForKey* aListener)
+{
+  mData.mMonitor.AssertCurrentThreadOwns();
+  MOZ_ASSERT(!IsKeyUsable(aKey));
+  MOZ_ASSERT(aListener);
+  mData.mWaitForKeys.AppendElement(WaitForKeys(aKey, aListener));
+}
+
+void
+CDMCaps::AutoLock::GetKeyStatusesForSession(const nsAString& aSessionId,
+                                            nsTArray<KeyStatus>& aOutKeyStatuses)
+{
+  for (const KeyStatus& keyStatus : mData.mKeyStatuses) {
+    if (keyStatus.mSessionId.Equals(aSessionId)) {
+      aOutKeyStatuses.AppendElement(keyStatus);
+    }
+  }
+}
+
+void
+CDMCaps::AutoLock::GetSessionIdsForKeyId(const CencKeyId& aKeyId,
+                                         nsTArray<nsCString>& aOutSessionIds)
+{
+  for (const KeyStatus& keyStatus : mData.mKeyStatuses) {
+    if (keyStatus.mId == aKeyId) {
+      aOutSessionIds.AppendElement(NS_ConvertUTF16toUTF8(keyStatus.mSessionId));
+    }
+  }
+}
+
+bool
+CDMCaps::AutoLock::RemoveKeysForSession(const nsString& aSessionId)
+{
+  bool changed = false;
+  nsTArray<KeyStatus> statuses;
+  GetKeyStatusesForSession(aSessionId, statuses);
+  for (const KeyStatus& status : statuses) {
+    changed |= SetKeyStatus(status.mId,
+                            aSessionId,
+                            dom::Optional<dom::MediaKeyStatus>());
+  }
+  return changed;
+}
+
+} // namespace mozilla
diff --git a/dom/media/eme/CDMCaps.h b/dom/media/eme/CDMCaps.h
new file mode 100644
index 0000000000..7749bdc675
--- /dev/null
+++ b/dom/media/eme/CDMCaps.h
@@ -0,0 +1,113 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CDMCaps_h_
+#define CDMCaps_h_
+
+#include "gmp-decryption.h"
+#include "nsIThread.h"
+#include "nsTArray.h"
+#include "nsString.h"
+#include "SamplesWaitingForKey.h"
+
+#include "mozilla/Monitor.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/dom/MediaKeyStatusMapBinding.h" // For MediaKeyStatus
+#include "mozilla/dom/BindingDeclarations.h" // For Optional
+
+namespace mozilla {
+
+// CDM capabilities; what keys a CDMProxy can use.
+// Must be locked to access state.
+class CDMCaps {
+public:
+  CDMCaps();
+  ~CDMCaps();
+
+  struct KeyStatus {
+    KeyStatus(const CencKeyId& aId,
+              const nsString& aSessionId,
+              dom::MediaKeyStatus aStatus)
+      : mId(aId)
+      , mSessionId(aSessionId)
+      , mStatus(aStatus)
+    {}
+    KeyStatus(const KeyStatus& aOther)
+      : mId(aOther.mId)
+      , mSessionId(aOther.mSessionId)
+      , mStatus(aOther.mStatus)
+    {}
+    bool operator==(const KeyStatus& aOther) const {
+      return mId == aOther.mId &&
+             mSessionId == aOther.mSessionId;
+    };
+
+    CencKeyId mId;
+    nsString mSessionId;
+    dom::MediaKeyStatus mStatus;
+  };
+
+  // Locks the CDMCaps. It must be locked to access its shared state.
+  // Threadsafe when locked.
+  class MOZ_STACK_CLASS AutoLock {
+  public:
+    explicit AutoLock(CDMCaps& aKeyCaps);
+    ~AutoLock();
+
+    bool IsKeyUsable(const CencKeyId& aKeyId);
+
+    // Returns true if key status changed,
+    // i.e. the key status changed from usable to expired.
+    bool SetKeyStatus(const CencKeyId& aKeyId,
+                      const nsString& aSessionId,
+                      const dom::Optional<dom::MediaKeyStatus>& aStatus);
+
+    void GetKeyStatusesForSession(const nsAString& aSessionId,
+                                  nsTArray<KeyStatus>& aOutKeyStatuses);
+
+    void GetSessionIdsForKeyId(const CencKeyId& aKeyId,
+                               nsTArray<nsCString>& aOutSessionIds);
+
+    // Ensures all keys for a session are marked as 'unknown', i.e. removed.
+    // Returns true if a key status was changed.
+    bool RemoveKeysForSession(const nsString& aSessionId);
+
+    // Notifies the SamplesWaitingForKey when key become usable.
+    void NotifyWhenKeyIdUsable(const CencKeyId& aKey,
+                               SamplesWaitingForKey* aSamplesWaiting);
+  private:
+    // Not taking a strong ref, since this should be allocated on the stack.
+    CDMCaps& mData;
+  };
+
+private:
+  void Lock();
+  void Unlock();
+
+  struct WaitForKeys {
+    WaitForKeys(const CencKeyId& aKeyId,
+                SamplesWaitingForKey* aListener)
+      : mKeyId(aKeyId)
+      , mListener(aListener)
+    {}
+    CencKeyId mKeyId;
+    RefPtr<SamplesWaitingForKey> mListener;
+  };
+
+  Monitor mMonitor;
+
+  nsTArray<KeyStatus> mKeyStatuses;
+
+  nsTArray<WaitForKeys> mWaitForKeys;
+
+  // It is not safe to copy this object.
+  CDMCaps(const CDMCaps&) = delete;
+  CDMCaps& operator=(const CDMCaps&) = delete;
+};
+
+} // namespace mozilla
+
+#endif
diff --git a/dom/media/eme/CDMProxy.h b/dom/media/eme/CDMProxy.h
new file mode 100644
index 0000000000..f3f1add43f
--- /dev/null
+++ b/dom/media/eme/CDMProxy.h
@@ -0,0 +1,279 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CDMProxy_h_
+#define CDMProxy_h_
+
+#include "mozilla/CDMCaps.h"
+#include "mozilla/MozPromise.h"
+
+#include "mozilla/dom/MediaKeyMessageEvent.h"
+#include "mozilla/dom/MediaKeys.h"
+
+#include "nsIThread.h"
+
+namespace mozilla {
+class MediaRawData;
+
+enum DecryptStatus {
+  Ok = 0,
+  GenericErr = 1,
+  NoKeyErr = 2,
+  AbortedErr = 3,
+};
+
+struct DecryptResult {
+  DecryptResult(DecryptStatus aStatus, MediaRawData* aSample)
+    : mStatus(aStatus)
+    , mSample(aSample)
+  {}
+  DecryptStatus mStatus;
+  RefPtr<MediaRawData> mSample;
+};
+
+class CDMKeyInfo {
+public:
+  explicit CDMKeyInfo(const nsTArray<uint8_t>& aKeyId)
+    : mKeyId(aKeyId)
+    , mStatus()
+  {}
+
+  CDMKeyInfo(const nsTArray<uint8_t>& aKeyId,
+             const dom::Optional<dom::MediaKeyStatus>& aStatus)
+    : mKeyId(aKeyId)
+    , mStatus(aStatus.Value())
+  {}
+
+  // The copy-ctor and copy-assignment operator for Optional<T> are declared as
+  // delete, so override CDMKeyInfo copy-ctor for nsTArray operations.
+  CDMKeyInfo(const CDMKeyInfo& aKeyInfo)
+  {
+    mKeyId = aKeyInfo.mKeyId;
+    if (aKeyInfo.mStatus.WasPassed()) {
+      mStatus.Construct(aKeyInfo.mStatus.Value());
+    }
+  }
+
+  nsTArray<uint8_t> mKeyId;
+  dom::Optional<dom::MediaKeyStatus> mStatus;
+};
+
+typedef int64_t UnixTime;
+
+// Proxies calls CDM, and proxies calls back.
+// Note: Promises are passed in via a PromiseId, so that the ID can be
+// passed via IPC to the CDM, which can then signal when to reject or
+// resolve the promise using its PromiseId.
+class CDMProxy {
+protected:
+  typedef dom::PromiseId PromiseId;
+  typedef dom::MediaKeySessionType MediaKeySessionType;
+public:
+
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) = 0;
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) = 0;
+
+  typedef MozPromise<DecryptResult, DecryptResult, /* IsExclusive = */ true> DecryptPromise;
+
+  // Main thread only.
+  CDMProxy(dom::MediaKeys* aKeys,
+           const nsAString& aKeySystem,
+           bool aDistinctiveIdentifierRequired,
+           bool aPersistentStateRequired)
+    : mKeys(aKeys)
+    , mKeySystem(aKeySystem)
+    , mDistinctiveIdentifierRequired(aDistinctiveIdentifierRequired)
+    , mPersistentStateRequired(aPersistentStateRequired)
+  {}
+
+  // Main thread only.
+  // Loads the CDM corresponding to mKeySystem.
+  // Calls MediaKeys::OnCDMCreated() when the CDM is created.
+  virtual void Init(PromiseId aPromiseId,
+                    const nsAString& aOrigin,
+                    const nsAString& aTopLevelOrigin,
+                    const nsAString& aName,
+                    bool aInPrivateBrowsing) = 0;
+
+  virtual void OnSetDecryptorId(uint32_t aId) {}
+
+  // Main thread only.
+  // Uses the CDM to create a key session.
+  // Calls MediaKeys::OnSessionActivated() when session is created.
+  // Assumes ownership of (Move()s) aInitData's contents.
+  virtual void CreateSession(uint32_t aCreateSessionToken,
+                             MediaKeySessionType aSessionType,
+                             PromiseId aPromiseId,
+                             const nsAString& aInitDataType,
+                             nsTArray<uint8_t>& aInitData) = 0;
+
+  // Main thread only.
+  // Uses the CDM to load a presistent session stored on disk.
+  // Calls MediaKeys::OnSessionActivated() when session is loaded.
+  virtual void LoadSession(PromiseId aPromiseId,
+                           const nsAString& aSessionId) = 0;
+
+  // Main thread only.
+  // Sends a new certificate to the CDM.
+  // Calls MediaKeys->ResolvePromise(aPromiseId) after the CDM has
+  // processed the request.
+  // Assumes ownership of (Move()s) aCert's contents.
+  virtual void SetServerCertificate(PromiseId aPromiseId,
+                                    nsTArray<uint8_t>& aCert) = 0;
+
+  // Main thread only.
+  // Sends an update to the CDM.
+  // Calls MediaKeys->ResolvePromise(aPromiseId) after the CDM has
+  // processed the request.
+  // Assumes ownership of (Move()s) aResponse's contents.
+  virtual void UpdateSession(const nsAString& aSessionId,
+                             PromiseId aPromiseId,
+                             nsTArray<uint8_t>& aResponse) = 0;
+
+  // Main thread only.
+  // Calls MediaKeys->ResolvePromise(aPromiseId) after the CDM has
+  // processed the request.
+  // If processing this operation results in the session actually closing,
+  // we also call MediaKeySession::OnClosed(), which in turn calls
+  // MediaKeys::OnSessionClosed().
+  virtual void CloseSession(const nsAString& aSessionId,
+                            PromiseId aPromiseId) = 0;
+
+  // Main thread only.
+  // Removes all data for a persisent session.
+  // Calls MediaKeys->ResolvePromise(aPromiseId) after the CDM has
+  // processed the request.
+  virtual void RemoveSession(const nsAString& aSessionId,
+                             PromiseId aPromiseId) = 0;
+
+  // Main thread only.
+  virtual void Shutdown() = 0;
+
+  // Main thread only.
+  virtual void Terminated() = 0;
+
+  // Threadsafe.
+  virtual const nsCString& GetNodeId() const = 0;
+
+  // Main thread only.
+  virtual void OnSetSessionId(uint32_t aCreateSessionToken,
+                              const nsAString& aSessionId) = 0;
+
+  // Main thread only.
+  virtual void OnResolveLoadSessionPromise(uint32_t aPromiseId,
+                                           bool aSuccess) = 0;
+
+  // Main thread only.
+  virtual void OnSessionMessage(const nsAString& aSessionId,
+                                dom::MediaKeyMessageType aMessageType,
+                                nsTArray<uint8_t>& aMessage) = 0;
+
+  // Main thread only.
+  virtual void OnExpirationChange(const nsAString& aSessionId,
+                                  UnixTime aExpiryTime) = 0;
+
+  // Main thread only.
+  virtual void OnSessionClosed(const nsAString& aSessionId) = 0;
+
+  // Main thread only.
+  virtual void OnSessionError(const nsAString& aSessionId,
+                              nsresult aException,
+                              uint32_t aSystemCode,
+                              const nsAString& aMsg) = 0;
+
+  // Main thread only.
+  virtual void OnRejectPromise(uint32_t aPromiseId,
+                               nsresult aDOMException,
+                               const nsCString& aMsg) = 0;
+
+  virtual RefPtr<DecryptPromise> Decrypt(MediaRawData* aSample) = 0;
+
+  // Owner thread only.
+  virtual void OnDecrypted(uint32_t aId,
+                           DecryptStatus aResult,
+                           const nsTArray<uint8_t>& aDecryptedData) = 0;
+
+  // Reject promise with DOMException corresponding to aExceptionCode.
+  // Can be called from any thread.
+  virtual void RejectPromise(PromiseId aId,
+                             nsresult aExceptionCode,
+                             const nsCString& aReason) = 0;
+
+  // Resolves promise with "undefined".
+  // Can be called from any thread.
+  virtual void ResolvePromise(PromiseId aId) = 0;
+
+  // Threadsafe.
+  virtual const nsString& KeySystem() const = 0;
+
+  virtual  CDMCaps& Capabilites() = 0;
+
+  // Main thread only.
+  virtual void OnKeyStatusesChange(const nsAString& aSessionId) = 0;
+
+  virtual void GetSessionIdsForKeyId(const nsTArray<uint8_t>& aKeyId,
+                                     nsTArray<nsCString>& aSessionIds) = 0;
+
+#ifdef DEBUG
+  virtual bool IsOnOwnerThread() = 0;
+#endif
+
+  virtual uint32_t GetDecryptorId() { return 0; }
+
+protected:
+  virtual ~CDMProxy() {}
+
+  // Helper to enforce that a raw pointer is only accessed on the main thread.
+  template<class Type>
+  class MainThreadOnlyRawPtr {
+  public:
+    explicit MainThreadOnlyRawPtr(Type* aPtr)
+      : mPtr(aPtr)
+    {
+      MOZ_ASSERT(NS_IsMainThread());
+    }
+
+    bool IsNull() const {
+      MOZ_ASSERT(NS_IsMainThread());
+      return !mPtr;
+    }
+
+    void Clear() {
+      MOZ_ASSERT(NS_IsMainThread());
+      mPtr = nullptr;
+    }
+
+    Type* operator->() const MOZ_NO_ADDREF_RELEASE_ON_RETURN {
+      MOZ_ASSERT(NS_IsMainThread());
+      return mPtr;
+    }
+  private:
+    Type* mPtr;
+  };
+
+  // Our reference back to the MediaKeys object.
+  // WARNING: This is a non-owning reference that is cleared by MediaKeys
+  // destructor. only use on main thread, and always nullcheck before using!
+  MainThreadOnlyRawPtr<dom::MediaKeys> mKeys;
+
+  const nsString mKeySystem;
+
+  // Onwer specified thread. e.g. Gecko Media Plugin thread.
+  // All interactions with the out-of-process EME plugin must come from this thread.
+  RefPtr<nsIThread> mOwnerThread;
+
+  nsCString mNodeId;
+
+  CDMCaps mCapabilites;
+
+  const bool mDistinctiveIdentifierRequired;
+  const bool mPersistentStateRequired;
+};
+
+
+} // namespace mozilla
+
+#endif // CDMProxy_h_
diff --git a/dom/media/eme/DecryptorProxyCallback.h b/dom/media/eme/DecryptorProxyCallback.h
new file mode 100644
index 0000000000..c1fcb49a4f
--- /dev/null
+++ b/dom/media/eme/DecryptorProxyCallback.h
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DecryptorProxyCallback_h_
+#define DecryptorProxyCallback_h_
+
+#include "mozilla/dom/MediaKeyStatusMapBinding.h" // For MediaKeyStatus
+#include "mozilla/dom/MediaKeyMessageEventBinding.h" // For MediaKeyMessageType
+#include "mozilla/CDMProxy.h"
+
+class DecryptorProxyCallback {
+public:
+
+  virtual ~DecryptorProxyCallback() {}
+
+  virtual void SetDecryptorId(uint32_t aId) = 0;
+
+  virtual void SetSessionId(uint32_t aCreateSessionId,
+                            const nsCString& aSessionId) = 0;
+
+  virtual void ResolveLoadSessionPromise(uint32_t aPromiseId,
+                                         bool aSuccess) = 0;
+
+  virtual void ResolvePromise(uint32_t aPromiseId) = 0;
+
+  virtual void RejectPromise(uint32_t aPromiseId,
+                             nsresult aException,
+                             const nsCString& aSessionId) = 0;
+
+  virtual void SessionMessage(const nsCString& aSessionId,
+                              mozilla::dom::MediaKeyMessageType aMessageType,
+                              const nsTArray<uint8_t>& aMessage) = 0;
+
+  virtual void ExpirationChange(const nsCString& aSessionId,
+                                mozilla::UnixTime aExpiryTime) = 0;
+
+  virtual void SessionClosed(const nsCString& aSessionId) = 0;
+
+  virtual void SessionError(const nsCString& aSessionId,
+                            nsresult aException,
+                            uint32_t aSystemCode,
+                            const nsCString& aMessage) = 0;
+
+  virtual void Decrypted(uint32_t aId,
+                         mozilla::DecryptStatus aResult,
+                         const nsTArray<uint8_t>& aDecryptedData) = 0;
+
+  virtual void BatchedKeyStatusChanged(const nsCString& aSessionId,
+                                       const nsTArray<mozilla::CDMKeyInfo>& aKeyInfos) = 0;
+};
+
+#endif
diff --git a/dom/media/eme/DetailedPromise.cpp b/dom/media/eme/DetailedPromise.cpp
new file mode 100644
index 0000000000..5893bea2ee
--- /dev/null
+++ b/dom/media/eme/DetailedPromise.cpp
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DetailedPromise.h"
+#include "mozilla/dom/DOMException.h"
+#include "nsPrintfCString.h"
+
+namespace mozilla {
+namespace dom {
+
+DetailedPromise::DetailedPromise(nsIGlobalObject* aGlobal,
+                                 const nsACString& aName)
+  : Promise(aGlobal)
+  , mName(aName)
+  , mResponded(false)
+  , mStartTime(TimeStamp::Now())
+{
+}
+
+DetailedPromise::DetailedPromise(nsIGlobalObject* aGlobal,
+                                 const nsACString& aName,
+                                 Telemetry::ID aSuccessLatencyProbe,
+                                 Telemetry::ID aFailureLatencyProbe)
+  : DetailedPromise(aGlobal, aName)
+{
+  mSuccessLatencyProbe.Construct(aSuccessLatencyProbe);
+  mFailureLatencyProbe.Construct(aFailureLatencyProbe);
+}
+
+DetailedPromise::~DetailedPromise()
+{
+  // It would be nice to assert that mResponded is identical to
+  // GetPromiseState() == PromiseState::Rejected.  But by now we've been
+  // unlinked, so don't have a reference to our actual JS Promise object
+  // anymore.
+  MaybeReportTelemetry(Failed);
+}
+
+void
+DetailedPromise::MaybeReject(nsresult aArg, const nsACString& aReason)
+{
+  nsPrintfCString msg("%s promise rejected 0x%x '%s'", mName.get(), aArg,
+                      PromiseFlatCString(aReason).get());
+  EME_LOG(msg.get());
+
+  MaybeReportTelemetry(Failed);
+
+  LogToBrowserConsole(NS_ConvertUTF8toUTF16(msg));
+
+  ErrorResult rv;
+  rv.ThrowDOMException(aArg, aReason);
+  Promise::MaybeReject(rv);
+}
+
+void
+DetailedPromise::MaybeReject(ErrorResult&, const nsACString& aReason)
+{
+  NS_NOTREACHED("nsresult expected in MaybeReject()");
+}
+
+/* static */ already_AddRefed<DetailedPromise>
+DetailedPromise::Create(nsIGlobalObject* aGlobal,
+                        ErrorResult& aRv,
+                        const nsACString& aName)
+{
+  RefPtr<DetailedPromise> promise = new DetailedPromise(aGlobal, aName);
+  promise->CreateWrapper(nullptr, aRv);
+  return aRv.Failed() ? nullptr : promise.forget();
+}
+
+/* static */ already_AddRefed<DetailedPromise>
+DetailedPromise::Create(nsIGlobalObject* aGlobal,
+                        ErrorResult& aRv,
+                        const nsACString& aName,
+                        Telemetry::ID aSuccessLatencyProbe,
+                        Telemetry::ID aFailureLatencyProbe)
+{
+  RefPtr<DetailedPromise> promise = new DetailedPromise(aGlobal, aName, aSuccessLatencyProbe, aFailureLatencyProbe);
+  promise->CreateWrapper(nullptr, aRv);
+  return aRv.Failed() ? nullptr : promise.forget();
+}
+
+void
+DetailedPromise::MaybeReportTelemetry(Status aStatus)
+{
+  if (mResponded) {
+    return;
+  }
+  mResponded = true;
+  if (!mSuccessLatencyProbe.WasPassed() || !mFailureLatencyProbe.WasPassed()) {
+    return;
+  }
+  uint32_t latency = (TimeStamp::Now() - mStartTime).ToMilliseconds();
+  EME_LOG("%s %s latency %ums reported via telemetry", mName.get(),
+          ((aStatus == Succeeded) ? "succcess" : "failure"), latency);
+  Telemetry::ID tid = (aStatus == Succeeded) ? mSuccessLatencyProbe.Value()
+                                             : mFailureLatencyProbe.Value();
+  Telemetry::Accumulate(tid, latency);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/DetailedPromise.h b/dom/media/eme/DetailedPromise.h
new file mode 100644
index 0000000000..83e40c0223
--- /dev/null
+++ b/dom/media/eme/DetailedPromise.h
@@ -0,0 +1,73 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __DetailedPromise_h__
+#define __DetailedPromise_h__
+
+#include "mozilla/dom/Promise.h"
+#include "mozilla/Telemetry.h"
+#include "EMEUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+/*
+ * This is pretty horrible; bug 1160445.
+ * Extend Promise to add custom DOMException messages on rejection.
+ * Get rid of this once we've ironed out EME errors in the wild.
+ */
+class DetailedPromise : public Promise
+{
+public:
+  static already_AddRefed<DetailedPromise>
+  Create(nsIGlobalObject* aGlobal,
+         ErrorResult& aRv,
+         const nsACString& aName);
+
+  static already_AddRefed<DetailedPromise>
+  Create(nsIGlobalObject* aGlobal, ErrorResult& aRv,
+         const nsACString& aName,
+         Telemetry::ID aSuccessLatencyProbe,
+         Telemetry::ID aFailureLatencyProbe);
+
+  template <typename T>
+  void MaybeResolve(const T& aArg)
+  {
+    EME_LOG("%s promise resolved", mName.get());
+    MaybeReportTelemetry(Succeeded);
+    Promise::MaybeResolve<T>(aArg);
+  }
+
+  void MaybeReject(nsresult aArg) = delete;
+  void MaybeReject(nsresult aArg, const nsACString& aReason);
+
+  void MaybeReject(ErrorResult& aArg) = delete;
+  void MaybeReject(ErrorResult&, const nsACString& aReason);
+
+private:
+  explicit DetailedPromise(nsIGlobalObject* aGlobal,
+                           const nsACString& aName);
+
+  explicit DetailedPromise(nsIGlobalObject* aGlobal,
+                           const nsACString& aName,
+                           Telemetry::ID aSuccessLatencyProbe,
+                           Telemetry::ID aFailureLatencyProbe);
+  virtual ~DetailedPromise();
+
+  enum Status { Succeeded, Failed };
+  void MaybeReportTelemetry(Status aStatus);
+
+  nsCString mName;
+  bool mResponded;
+  TimeStamp mStartTime;
+  Optional<Telemetry::ID> mSuccessLatencyProbe;
+  Optional<Telemetry::ID> mFailureLatencyProbe;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // __DetailedPromise_h__
diff --git a/dom/media/eme/EMEUtils.cpp b/dom/media/eme/EMEUtils.cpp
new file mode 100644
index 0000000000..c248b3a24c
--- /dev/null
+++ b/dom/media/eme/EMEUtils.cpp
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/EMEUtils.h"
+#include "mozilla/dom/UnionTypes.h"
+
+namespace mozilla {
+
+LogModule* GetEMELog() {
+  static LazyLogModule log("EME");
+  return log;
+}
+
+LogModule* GetEMEVerboseLog() {
+  static LazyLogModule log("EMEV");
+  return log;
+}
+
+ArrayData
+GetArrayBufferViewOrArrayBufferData(const dom::ArrayBufferViewOrArrayBuffer& aBufferOrView)
+{
+  MOZ_ASSERT(aBufferOrView.IsArrayBuffer() || aBufferOrView.IsArrayBufferView());
+  if (aBufferOrView.IsArrayBuffer()) {
+    const dom::ArrayBuffer& buffer = aBufferOrView.GetAsArrayBuffer();
+    buffer.ComputeLengthAndData();
+    return ArrayData(buffer.Data(), buffer.Length());
+  } else if (aBufferOrView.IsArrayBufferView()) {
+    const dom::ArrayBufferView& bufferview = aBufferOrView.GetAsArrayBufferView();
+    bufferview.ComputeLengthAndData();
+    return ArrayData(bufferview.Data(), bufferview.Length());
+  }
+  return ArrayData(nullptr, 0);
+}
+
+void
+CopyArrayBufferViewOrArrayBufferData(const dom::ArrayBufferViewOrArrayBuffer& aBufferOrView,
+                                     nsTArray<uint8_t>& aOutData)
+{
+  ArrayData data = GetArrayBufferViewOrArrayBufferData(aBufferOrView);
+  aOutData.Clear();
+  if (!data.IsValid()) {
+    return;
+  }
+  aOutData.AppendElements(data.mData, data.mLength);
+}
+
+bool
+IsClearkeyKeySystem(const nsAString& aKeySystem)
+{
+  return !CompareUTF8toUTF16(kEMEKeySystemClearkey, aKeySystem);
+}
+
+bool
+IsPrimetimeKeySystem(const nsAString& aKeySystem)
+{
+  return !CompareUTF8toUTF16(kEMEKeySystemPrimetime, aKeySystem);
+}
+
+bool
+IsWidevineKeySystem(const nsAString& aKeySystem)
+{
+  return !CompareUTF8toUTF16(kEMEKeySystemWidevine, aKeySystem);
+}
+
+nsString
+KeySystemToGMPName(const nsAString& aKeySystem)
+{
+  if (IsPrimetimeKeySystem(aKeySystem)) {
+    return NS_LITERAL_STRING("gmp-eme-adobe");
+  }
+  if (IsClearkeyKeySystem(aKeySystem)) {
+    return NS_LITERAL_STRING("gmp-clearkey");
+  }
+  if (IsWidevineKeySystem(aKeySystem)) {
+    return NS_LITERAL_STRING("gmp-widevinecdm");
+  }
+  MOZ_ASSERT(false, "We should only call this for known GMPs");
+  return EmptyString();
+}
+
+CDMType
+ToCDMTypeTelemetryEnum(const nsString& aKeySystem)
+{
+  if (IsWidevineKeySystem(aKeySystem)) {
+    return CDMType::eWidevine;
+  } else if (IsClearkeyKeySystem(aKeySystem)) {
+    return CDMType::eClearKey;
+  } else if (IsPrimetimeKeySystem(aKeySystem)) {
+    return CDMType::ePrimetime;
+  }
+  return CDMType::eUnknown;
+}
+
+} // namespace mozilla
diff --git a/dom/media/eme/EMEUtils.h b/dom/media/eme/EMEUtils.h
new file mode 100644
index 0000000000..1794f8462b
--- /dev/null
+++ b/dom/media/eme/EMEUtils.h
@@ -0,0 +1,107 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef EME_LOG_H_
+#define EME_LOG_H_
+
+#include "VideoUtils.h"
+#include "mozilla/Logging.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+
+namespace dom {
+class ArrayBufferViewOrArrayBuffer;
+}
+
+#ifndef EME_LOG
+  LogModule* GetEMELog();
+  #define EME_LOG(...) MOZ_LOG(GetEMELog(), mozilla::LogLevel::Debug, (__VA_ARGS__))
+  #define EME_LOG_ENABLED() MOZ_LOG_TEST(GetEMELog(), mozilla::LogLevel::Debug)
+#endif
+
+#ifndef EME_VERBOSE_LOG
+  LogModule* GetEMEVerboseLog();
+  #define EME_VERBOSE_LOG(...) MOZ_LOG(GetEMEVerboseLog(), mozilla::LogLevel::Debug, (__VA_ARGS__))
+#else
+  #ifndef EME_LOG
+    #define EME_LOG(...)
+  #endif
+
+  #ifndef EME_VERBOSE_LOG
+    #define EME_VERBOSE_LOG(...)
+  #endif
+#endif
+
+// Helper function to extract a copy of data coming in from JS in an
+// (ArrayBuffer or ArrayBufferView) IDL typed function argument.
+//
+// Only call this on a properly initialized ArrayBufferViewOrArrayBuffer.
+void
+CopyArrayBufferViewOrArrayBufferData(const dom::ArrayBufferViewOrArrayBuffer& aBufferOrView,
+                                     nsTArray<uint8_t>& aOutData);
+
+struct ArrayData {
+  explicit ArrayData(const uint8_t* aData, size_t aLength)
+    : mData(aData)
+    , mLength(aLength)
+  {
+  }
+  const uint8_t* mData;
+  const size_t mLength;
+  bool IsValid() const {
+    return mData != nullptr && mLength != 0;
+  }
+  bool operator== (const nsTArray<uint8_t>& aOther) const {
+    return mLength == aOther.Length() &&
+           memcmp(mData, aOther.Elements(), mLength) == 0;
+  }
+};
+
+// Helper function to extract data coming in from JS in an
+// (ArrayBuffer or ArrayBufferView) IDL typed function argument.
+//
+// Be *very* careful with this!
+//
+// Only use returned ArrayData inside the lifetime of the
+// ArrayBufferViewOrArrayBuffer; the ArrayData struct does not contain
+// a copy of the data!
+//
+// And do *not* call out to anything that could call into JavaScript,
+// while the ArrayData is live, as then all bets about the data not changing
+// are off! No calls into JS, no calls into JS-implemented WebIDL or XPIDL,
+// nothing. Beware!
+//
+// Only call this on a properly initialized ArrayBufferViewOrArrayBuffer.
+ArrayData
+GetArrayBufferViewOrArrayBufferData(const dom::ArrayBufferViewOrArrayBuffer& aBufferOrView);
+
+nsString
+KeySystemToGMPName(const nsAString& aKeySystem);
+
+bool
+IsClearkeyKeySystem(const nsAString& aKeySystem);
+
+bool
+IsPrimetimeKeySystem(const nsAString& aKeySystem);
+
+bool
+IsWidevineKeySystem(const nsAString& aKeySystem);
+
+enum CDMType {
+  eClearKey = 0,
+  ePrimetime = 1,
+  eWidevine = 2,
+  eUnknown = 3
+};
+
+CDMType
+ToCDMTypeTelemetryEnum(const nsString& aKeySystem);
+
+} // namespace mozilla
+
+#endif // EME_LOG_H_
diff --git a/dom/media/eme/MediaEncryptedEvent.cpp b/dom/media/eme/MediaEncryptedEvent.cpp
new file mode 100644
index 0000000000..8e2595fcb9
--- /dev/null
+++ b/dom/media/eme/MediaEncryptedEvent.cpp
@@ -0,0 +1,129 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaEncryptedEvent.h"
+#include "mozilla/dom/MediaEncryptedEventBinding.h"
+#include "nsContentUtils.h"
+#include "jsfriendapi.h"
+#include "nsINode.h"
+#include "mozilla/dom/MediaKeys.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(MediaEncryptedEvent)
+
+NS_IMPL_ADDREF_INHERITED(MediaEncryptedEvent, Event)
+NS_IMPL_RELEASE_INHERITED(MediaEncryptedEvent, Event)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MediaEncryptedEvent, Event)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(MediaEncryptedEvent, Event)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mInitData)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(MediaEncryptedEvent, Event)
+  tmp->mInitData = nullptr;
+  mozilla::DropJSObjects(this);
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MediaEncryptedEvent)
+NS_INTERFACE_MAP_END_INHERITING(Event)
+
+MediaEncryptedEvent::MediaEncryptedEvent(EventTarget* aOwner)
+  : Event(aOwner, nullptr, nullptr)
+{
+  mozilla::HoldJSObjects(this);
+}
+
+MediaEncryptedEvent::~MediaEncryptedEvent()
+{
+  mInitData = nullptr;
+  mozilla::DropJSObjects(this);
+}
+
+JSObject*
+MediaEncryptedEvent::WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaEncryptedEventBinding::Wrap(aCx, this, aGivenProto);
+}
+
+already_AddRefed<MediaEncryptedEvent>
+MediaEncryptedEvent::Constructor(EventTarget* aOwner)
+{
+  RefPtr<MediaEncryptedEvent> e = new MediaEncryptedEvent(aOwner);
+  e->InitEvent(NS_LITERAL_STRING("encrypted"), false, false);
+  e->SetTrusted(true);
+  return e.forget();
+}
+
+already_AddRefed<MediaEncryptedEvent>
+MediaEncryptedEvent::Constructor(EventTarget* aOwner,
+                                 const nsAString& aInitDataType,
+                                 const nsTArray<uint8_t>& aInitData)
+{
+  RefPtr<MediaEncryptedEvent> e = new MediaEncryptedEvent(aOwner);
+  e->InitEvent(NS_LITERAL_STRING("encrypted"), false, false);
+  e->mInitDataType = aInitDataType;
+  e->mRawInitData = aInitData;
+  e->SetTrusted(true);
+  return e.forget();
+}
+
+already_AddRefed<MediaEncryptedEvent>
+MediaEncryptedEvent::Constructor(const GlobalObject& aGlobal,
+                                 const nsAString& aType,
+                                 const MediaKeyNeededEventInit& aEventInitDict,
+                                 ErrorResult& aRv)
+{
+  nsCOMPtr<EventTarget> owner = do_QueryInterface(aGlobal.GetAsSupports());
+  RefPtr<MediaEncryptedEvent> e = new MediaEncryptedEvent(owner);
+  bool trusted = e->Init(owner);
+  e->InitEvent(aType, aEventInitDict.mBubbles, aEventInitDict.mCancelable);
+  e->mInitDataType = aEventInitDict.mInitDataType;
+  if (!aEventInitDict.mInitData.IsNull()) {
+    const auto& a = aEventInitDict.mInitData.Value();
+    a.ComputeLengthAndData();
+    e->mInitData = ArrayBuffer::Create(aGlobal.Context(),
+                                       a.Length(),
+                                       a.Data());
+    if (!e->mInitData) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return nullptr;
+    }
+  }
+  e->SetTrusted(trusted);
+  return e.forget();
+}
+
+void
+MediaEncryptedEvent::GetInitDataType(nsString& aRetVal) const
+{
+  aRetVal = mInitDataType;
+}
+
+void
+MediaEncryptedEvent::GetInitData(JSContext* cx,
+                                 JS::MutableHandle<JSObject*> aData,
+                                 ErrorResult& aRv)
+{
+  if (mRawInitData.Length()) {
+    mInitData = ArrayBuffer::Create(cx,
+                                    this,
+                                    mRawInitData.Length(),
+                                    mRawInitData.Elements());
+    if (!mInitData) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return;
+    }
+    mRawInitData.Clear();
+  }
+  aData.set(mInitData);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaEncryptedEvent.h b/dom/media/eme/MediaEncryptedEvent.h
new file mode 100644
index 0000000000..806fccad69
--- /dev/null
+++ b/dom/media/eme/MediaEncryptedEvent.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeyNeededEvent_h__
+#define mozilla_dom_MediaKeyNeededEvent_h__
+
+#include "mozilla/dom/MediaEncryptedEventBinding.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+#include "nsCOMPtr.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/dom/BindingUtils.h"
+#include "js/TypeDecls.h"
+
+namespace mozilla {
+namespace dom {
+
+class MediaEncryptedEvent final : public Event
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(MediaEncryptedEvent, Event)
+protected:
+  virtual ~MediaEncryptedEvent();
+  explicit MediaEncryptedEvent(EventTarget* aOwner);
+
+  nsString mInitDataType;
+  JS::Heap<JSObject*> mInitData;
+
+public:
+
+  JSObject* WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  static already_AddRefed<MediaEncryptedEvent>
+  Constructor(EventTarget* aOwner);
+
+  static already_AddRefed<MediaEncryptedEvent>
+  Constructor(EventTarget* aOwner,
+              const nsAString& aInitDataType,
+              const nsTArray<uint8_t>& aInitData);
+
+  static already_AddRefed<MediaEncryptedEvent>
+  Constructor(const GlobalObject& aGlobal,
+              const nsAString& aType,
+              const MediaKeyNeededEventInit& aEventInitDict,
+              ErrorResult& aRv);
+
+  void GetInitDataType(nsString& aRetVal) const;
+
+  void GetInitData(JSContext* cx,
+                   JS::MutableHandle<JSObject*> aData,
+                   ErrorResult& aRv);
+private:
+  nsTArray<uint8_t> mRawInitData;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_MediaKeyNeededEvent_h__
diff --git a/dom/media/eme/MediaKeyError.cpp b/dom/media/eme/MediaKeyError.cpp
new file mode 100644
index 0000000000..635c343642
--- /dev/null
+++ b/dom/media/eme/MediaKeyError.cpp
@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaKeyError.h"
+#include "mozilla/dom/MediaKeyErrorBinding.h"
+#include "nsContentUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+MediaKeyError::MediaKeyError(EventTarget* aOwner, uint32_t aSystemCode)
+  : Event(aOwner, nullptr, nullptr)
+  , mSystemCode(aSystemCode)
+{
+  InitEvent(NS_LITERAL_STRING("error"), false, false);
+}
+
+MediaKeyError::~MediaKeyError()
+{
+}
+
+uint32_t
+MediaKeyError::SystemCode() const
+{
+  return mSystemCode;
+}
+
+JSObject*
+MediaKeyError::WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeyErrorBinding::Wrap(aCx, this, aGivenProto);
+}
+
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeyError.h b/dom/media/eme/MediaKeyError.h
new file mode 100644
index 0000000000..df79b2c959
--- /dev/null
+++ b/dom/media/eme/MediaKeyError.h
@@ -0,0 +1,38 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeyError_h
+#define mozilla_dom_MediaKeyError_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "nsWrapperCache.h"
+#include "mozilla/dom/Event.h"
+#include "js/TypeDecls.h"
+
+namespace mozilla {
+namespace dom {
+
+class MediaKeyError final : public Event
+{
+public:
+  NS_FORWARD_TO_EVENT
+
+  MediaKeyError(EventTarget* aOwner, uint32_t aSystemCode);
+  ~MediaKeyError();
+
+  JSObject* WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  uint32_t SystemCode() const;
+
+private:
+  uint32_t mSystemCode;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif
diff --git a/dom/media/eme/MediaKeyMessageEvent.cpp b/dom/media/eme/MediaKeyMessageEvent.cpp
new file mode 100644
index 0000000000..37c509e674
--- /dev/null
+++ b/dom/media/eme/MediaKeyMessageEvent.cpp
@@ -0,0 +1,122 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/MediaKeyMessageEvent.h"
+#include "mozilla/dom/MediaKeyMessageEventBinding.h"
+#include "js/GCAPI.h"
+#include "jsfriendapi.h"
+#include "mozilla/dom/Nullable.h"
+#include "mozilla/dom/PrimitiveConversions.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/dom/TypedArray.h"
+#include "nsContentUtils.h"
+#include "mozilla/dom/MediaKeys.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(MediaKeyMessageEvent)
+
+NS_IMPL_ADDREF_INHERITED(MediaKeyMessageEvent, Event)
+NS_IMPL_RELEASE_INHERITED(MediaKeyMessageEvent, Event)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MediaKeyMessageEvent, Event)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(MediaKeyMessageEvent, Event)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mMessage)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(MediaKeyMessageEvent, Event)
+  tmp->mMessage = nullptr;
+  mozilla::DropJSObjects(this);
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MediaKeyMessageEvent)
+NS_INTERFACE_MAP_END_INHERITING(Event)
+
+MediaKeyMessageEvent::MediaKeyMessageEvent(EventTarget* aOwner)
+  : Event(aOwner, nullptr, nullptr)
+{
+  mozilla::HoldJSObjects(this);
+}
+
+MediaKeyMessageEvent::~MediaKeyMessageEvent()
+{
+  mMessage = nullptr;
+  mozilla::DropJSObjects(this);
+}
+
+MediaKeyMessageEvent*
+MediaKeyMessageEvent::AsMediaKeyMessageEvent()
+{
+  return this;
+}
+
+JSObject*
+MediaKeyMessageEvent::WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeyMessageEventBinding::Wrap(aCx, this, aGivenProto);
+}
+
+already_AddRefed<MediaKeyMessageEvent>
+MediaKeyMessageEvent::Constructor(EventTarget* aOwner,
+                                  MediaKeyMessageType aMessageType,
+                                  const nsTArray<uint8_t>& aMessage)
+{
+  RefPtr<MediaKeyMessageEvent> e = new MediaKeyMessageEvent(aOwner);
+  e->InitEvent(NS_LITERAL_STRING("message"), false, false);
+  e->mMessageType = aMessageType;
+  e->mRawMessage = aMessage;
+  e->SetTrusted(true);
+  return e.forget();
+}
+
+already_AddRefed<MediaKeyMessageEvent>
+MediaKeyMessageEvent::Constructor(const GlobalObject& aGlobal,
+                                  const nsAString& aType,
+                                  const MediaKeyMessageEventInit& aEventInitDict,
+                                  ErrorResult& aRv)
+{
+  nsCOMPtr<EventTarget> owner = do_QueryInterface(aGlobal.GetAsSupports());
+  RefPtr<MediaKeyMessageEvent> e = new MediaKeyMessageEvent(owner);
+  bool trusted = e->Init(owner);
+  e->InitEvent(aType, aEventInitDict.mBubbles, aEventInitDict.mCancelable);
+  aEventInitDict.mMessage.ComputeLengthAndData();
+  e->mMessage = ArrayBuffer::Create(aGlobal.Context(),
+                                    aEventInitDict.mMessage.Length(),
+                                    aEventInitDict.mMessage.Data());
+  if (!e->mMessage) {
+    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    return nullptr;
+  }
+  e->mMessageType = aEventInitDict.mMessageType;
+  e->SetTrusted(trusted);
+  e->SetComposed(aEventInitDict.mComposed);
+  return e.forget();
+}
+
+void
+MediaKeyMessageEvent::GetMessage(JSContext* cx,
+                                 JS::MutableHandle<JSObject*> aMessage,
+                                 ErrorResult& aRv)
+{
+  if (!mMessage) {
+    mMessage = ArrayBuffer::Create(cx,
+                                   this,
+                                   mRawMessage.Length(),
+                                   mRawMessage.Elements());
+    if (!mMessage) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return;
+    }
+    mRawMessage.Clear();
+  }
+  aMessage.set(mMessage);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeyMessageEvent.h b/dom/media/eme/MediaKeyMessageEvent.h
new file mode 100644
index 0000000000..b6cc86dfaa
--- /dev/null
+++ b/dom/media/eme/MediaKeyMessageEvent.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeyMessageEvent_h__
+#define mozilla_dom_MediaKeyMessageEvent_h__
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+#include "nsCOMPtr.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/dom/TypedArray.h"
+#include "js/TypeDecls.h"
+#include "mozilla/dom/MediaKeyMessageEventBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+struct MediaKeyMessageEventInit;
+
+class MediaKeyMessageEvent final : public Event
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(MediaKeyMessageEvent, Event)
+protected:
+  virtual ~MediaKeyMessageEvent();
+  explicit MediaKeyMessageEvent(EventTarget* aOwner);
+
+  MediaKeyMessageType mMessageType;
+  JS::Heap<JSObject*> mMessage;
+
+public:
+  virtual MediaKeyMessageEvent* AsMediaKeyMessageEvent();
+
+  JSObject* WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  static already_AddRefed<MediaKeyMessageEvent>
+  Constructor(EventTarget* aOwner,
+              MediaKeyMessageType aMessageType,
+              const nsTArray<uint8_t>& aMessage);
+
+  static already_AddRefed<MediaKeyMessageEvent>
+  Constructor(const GlobalObject& aGlobal,
+              const nsAString& aType,
+              const MediaKeyMessageEventInit& aEventInitDict,
+              ErrorResult& aRv);
+
+  MediaKeyMessageType MessageType() const { return mMessageType; }
+
+  void GetMessage(JSContext* cx,
+                  JS::MutableHandle<JSObject*> aMessage,
+                  ErrorResult& aRv);
+
+private:
+  nsTArray<uint8_t> mRawMessage;
+};
+
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_MediaKeyMessageEvent_h__
diff --git a/dom/media/eme/MediaKeySession.cpp b/dom/media/eme/MediaKeySession.cpp
new file mode 100644
index 0000000000..d5eff3f773
--- /dev/null
+++ b/dom/media/eme/MediaKeySession.cpp
@@ -0,0 +1,674 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/HTMLMediaElement.h"
+#include "mozilla/dom/MediaKeySession.h"
+#include "mozilla/dom/MediaKeyError.h"
+#include "mozilla/dom/MediaKeyMessageEvent.h"
+#include "mozilla/dom/MediaEncryptedEvent.h"
+#include "mozilla/dom/MediaKeyStatusMap.h"
+#include "mozilla/dom/MediaKeySystemAccess.h"
+#include "mozilla/dom/KeyIdsInitDataBinding.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/CDMProxy.h"
+#include "mozilla/AsyncEventDispatcher.h"
+#include "mozilla/Move.h"
+#include "nsContentUtils.h"
+#include "mozilla/EMEUtils.h"
+#include "GMPUtils.h"
+#include "nsPrintfCString.h"
+#include "psshparser/PsshParser.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(MediaKeySession,
+                                   DOMEventTargetHelper,
+                                   mMediaKeyError,
+                                   mKeys,
+                                   mKeyStatusMap,
+                                   mClosed)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MediaKeySession)
+NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
+
+NS_IMPL_ADDREF_INHERITED(MediaKeySession, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(MediaKeySession, DOMEventTargetHelper)
+
+// Count of number of instances. Used to give each instance a
+// unique token.
+static uint32_t sMediaKeySessionNum = 0;
+
+// Max length of keyId in EME "keyIds" or WebM init data format, as enforced
+// by web platform tests.
+static const uint32_t MAX_KEY_ID_LENGTH = 512;
+
+// Max length of CENC PSSH init data tolerated, as enforced by web
+// platform tests.
+static const uint32_t MAX_CENC_INIT_DATA_LENGTH = 64 * 1024;
+
+
+MediaKeySession::MediaKeySession(JSContext* aCx,
+                                 nsPIDOMWindowInner* aParent,
+                                 MediaKeys* aKeys,
+                                 const nsAString& aKeySystem,
+                                 MediaKeySessionType aSessionType,
+                                 ErrorResult& aRv)
+  : DOMEventTargetHelper(aParent)
+  , mKeys(aKeys)
+  , mKeySystem(aKeySystem)
+  , mSessionType(aSessionType)
+  , mToken(sMediaKeySessionNum++)
+  , mIsClosed(false)
+  , mUninitialized(true)
+  , mKeyStatusMap(new MediaKeyStatusMap(aParent))
+  , mExpiration(JS::GenericNaN())
+{
+  EME_LOG("MediaKeySession[%p,''] ctor", this);
+
+  MOZ_ASSERT(aParent);
+  if (aRv.Failed()) {
+    return;
+  }
+  mClosed = MakePromise(aRv, NS_LITERAL_CSTRING("MediaKeys.createSession"));
+}
+
+void MediaKeySession::SetSessionId(const nsAString& aSessionId)
+{
+  EME_LOG("MediaKeySession[%p,'%s'] session Id set",
+          this, NS_ConvertUTF16toUTF8(aSessionId).get());
+
+  if (NS_WARN_IF(!mSessionId.IsEmpty())) {
+    return;
+  }
+  mSessionId = aSessionId;
+  mKeys->OnSessionIdReady(this);
+}
+
+MediaKeySession::~MediaKeySession()
+{
+}
+
+MediaKeyError*
+MediaKeySession::GetError() const
+{
+  return mMediaKeyError;
+}
+
+void
+MediaKeySession::GetKeySystem(nsString& aOutKeySystem) const
+{
+  aOutKeySystem.Assign(mKeySystem);
+}
+
+void
+MediaKeySession::GetSessionId(nsString& aSessionId) const
+{
+  aSessionId = GetSessionId();
+}
+
+const nsString&
+MediaKeySession::GetSessionId() const
+{
+  return mSessionId;
+}
+
+JSObject*
+MediaKeySession::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeySessionBinding::Wrap(aCx, this, aGivenProto);
+}
+
+double
+MediaKeySession::Expiration() const
+{
+  return mExpiration;
+}
+
+Promise*
+MediaKeySession::Closed() const
+{
+  return mClosed;
+}
+
+void
+MediaKeySession::UpdateKeyStatusMap()
+{
+  MOZ_ASSERT(!IsClosed());
+  if (!mKeys->GetCDMProxy()) {
+    return;
+  }
+
+  nsTArray<CDMCaps::KeyStatus> keyStatuses;
+  {
+    CDMCaps::AutoLock caps(mKeys->GetCDMProxy()->Capabilites());
+    caps.GetKeyStatusesForSession(mSessionId, keyStatuses);
+  }
+
+  mKeyStatusMap->Update(keyStatuses);
+
+  if (EME_LOG_ENABLED()) {
+    nsAutoCString message(
+      nsPrintfCString("MediaKeySession[%p,'%s'] key statuses change {",
+                      this, NS_ConvertUTF16toUTF8(mSessionId).get()));
+    using IntegerType = typename std::underlying_type<MediaKeyStatus>::type;
+    for (const CDMCaps::KeyStatus& status : keyStatuses) {
+      message.Append(nsPrintfCString(" (%s,%s)", ToBase64(status.mId).get(),
+        MediaKeyStatusValues::strings[static_cast<IntegerType>(status.mStatus)].value));
+    }
+    message.Append(" }");
+    EME_LOG(message.get());
+  }
+}
+
+MediaKeyStatusMap*
+MediaKeySession::KeyStatuses() const
+{
+  return mKeyStatusMap;
+}
+
+// The user agent MUST thoroughly validate the Initialization Data before
+// passing it to the CDM. This includes verifying that the length and
+// values of fields are reasonable, verifying that values are within
+// reasonable limits, and stripping irrelevant, unsupported, or unknown
+// data or fields. It is RECOMMENDED that user agents pre-parse, sanitize,
+// and/or generate a fully sanitized version of the Initialization Data.
+// If the Initialization Data format specified by initDataType supports
+// multiple entries, the user agent SHOULD remove entries that are not
+// needed by the CDM. The user agent MUST NOT re-order entries within
+// the Initialization Data.
+static bool
+ValidateInitData(const nsTArray<uint8_t>& aInitData, const nsAString& aInitDataType)
+{
+  if (aInitDataType.LowerCaseEqualsLiteral("webm")) {
+    // WebM initData consists of a single keyId. Ensure it's of reasonable length.
+    return aInitData.Length() <= MAX_KEY_ID_LENGTH;
+  } else if (aInitDataType.LowerCaseEqualsLiteral("cenc")) {
+    // Limit initData to less than 64KB.
+    if (aInitData.Length() > MAX_CENC_INIT_DATA_LENGTH) {
+      return false;
+    }
+    std::vector<std::vector<uint8_t>> keyIds;
+    return ParseCENCInitData(aInitData.Elements(), aInitData.Length(), keyIds);
+  } else if (aInitDataType.LowerCaseEqualsLiteral("keyids")) {
+    if (aInitData.Length() > MAX_KEY_ID_LENGTH) {
+      return false;
+    }
+    // Ensure that init data matches the expected JSON format.
+    mozilla::dom::KeyIdsInitData keyIds;
+    nsString json;
+    nsDependentCSubstring raw(reinterpret_cast<const char*>(aInitData.Elements()), aInitData.Length());
+    if (NS_FAILED(nsContentUtils::ConvertStringFromEncoding(NS_LITERAL_CSTRING("UTF-8"), raw, json))) {
+      return false;
+    }
+    if (!keyIds.Init(json)) {
+      return false;
+    }
+    if (keyIds.mKids.Length() == 0) {
+      return false;
+    }
+    for (const auto& kid : keyIds.mKids) {
+      if (kid.IsEmpty()) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+// Generates a license request based on the initData. A message of type
+// "license-request" or "individualization-request" will always be queued
+// if the algorithm succeeds and the promise is resolved.
+already_AddRefed<Promise>
+MediaKeySession::GenerateRequest(const nsAString& aInitDataType,
+                                 const ArrayBufferViewOrArrayBuffer& aInitData,
+                                 ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeySession.generateRequest")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  // If this object is closed, return a promise rejected with an InvalidStateError.
+  if (IsClosed()) {
+    EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() failed, closed",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+      NS_LITERAL_CSTRING("Session is closed in MediaKeySession.generateRequest()"));
+    return promise.forget();
+  }
+
+  // If this object's uninitialized value is false, return a promise rejected
+  // with an InvalidStateError.
+  if (!mUninitialized) {
+    EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() failed, uninitialized",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+      NS_LITERAL_CSTRING("Session is already initialized in MediaKeySession.generateRequest()"));
+    return promise.forget();
+  }
+
+  // Let this object's uninitialized value be false.
+  mUninitialized = false;
+
+  // If initDataType is the empty string, return a promise rejected
+  // with a newly created TypeError.
+  if (aInitDataType.IsEmpty()) {
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+      NS_LITERAL_CSTRING("Empty initDataType passed to MediaKeySession.generateRequest()"));
+    EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() failed, empty initDataType",
+      this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+
+  // If initData is an empty array, return a promise rejected with
+  // a newly created TypeError.
+  nsTArray<uint8_t> data;
+  CopyArrayBufferViewOrArrayBufferData(aInitData, data);
+  if (data.IsEmpty()) {
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+      NS_LITERAL_CSTRING("Empty initData passed to MediaKeySession.generateRequest()"));
+    EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() failed, empty initData",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+
+  // If the Key System implementation represented by this object's
+  // cdm implementation value does not support initDataType as an
+  // Initialization Data Type, return a promise rejected with a
+  // NotSupportedError. String comparison is case-sensitive.
+  if (!MediaKeySystemAccess::KeySystemSupportsInitDataType(mKeySystem, aInitDataType)) {
+    promise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
+      NS_LITERAL_CSTRING("Unsupported initDataType passed to MediaKeySession.generateRequest()"));
+    EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() failed, unsupported initDataType",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+
+  // Let init data be a copy of the contents of the initData parameter.
+  // Note: Handled by the CopyArrayBufferViewOrArrayBufferData call above.
+
+  // Let session type be this object's session type.
+
+  // Let promise be a new promise.
+
+  // Run the following steps in parallel:
+
+  // If the init data is not valid for initDataType, reject promise with
+  // a newly created TypeError.
+  if (!ValidateInitData(data, aInitDataType)) {
+    // If the preceding step failed, reject promise with a newly created TypeError.
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+      NS_LITERAL_CSTRING("initData sanitization failed in MediaKeySession.generateRequest()"));
+    EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() initData sanitization failed",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+
+  // Let sanitized init data be a validated and sanitized version of init data.
+
+  // If sanitized init data is empty, reject promise with a NotSupportedError.
+
+  // Note: Remaining steps of generateRequest method continue in CDM.
+
+  Telemetry::Accumulate(Telemetry::VIDEO_CDM_GENERATE_REQUEST_CALLED,
+                        ToCDMTypeTelemetryEnum(mKeySystem));
+
+  // Convert initData to base64 for easier logging.
+  // Note: CreateSession() Move()s the data out of the array, so we have
+  // to copy it here.
+  nsAutoCString base64InitData(ToBase64(data));
+  PromiseId pid = mKeys->StorePromise(promise);
+  mKeys->ConnectPendingPromiseIdWithToken(pid, Token());
+  mKeys->GetCDMProxy()->CreateSession(Token(),
+                                      mSessionType,
+                                      pid,
+                                      aInitDataType, data);
+
+  EME_LOG("MediaKeySession[%p,'%s'] GenerateRequest() sent, "
+          "promiseId=%d initData(base64)='%s' initDataType='%s'",
+          this,
+          NS_ConvertUTF16toUTF8(mSessionId).get(),
+          pid,
+          base64InitData.get(),
+          NS_ConvertUTF16toUTF8(aInitDataType).get());
+
+  return promise.forget();
+}
+
+already_AddRefed<Promise>
+MediaKeySession::Load(const nsAString& aSessionId, ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeySession.load")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  // 1. If this object is closed, return a promise rejected with an InvalidStateError.
+  if (IsClosed()) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Session is closed in MediaKeySession.load()"));
+    EME_LOG("MediaKeySession[%p,'%s'] Load() failed, closed",
+      this, NS_ConvertUTF16toUTF8(aSessionId).get());
+    return promise.forget();
+  }
+
+  // 2.If this object's uninitialized value is false, return a promise rejected
+  // with an InvalidStateError.
+  if (!mUninitialized) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Session is already initialized in MediaKeySession.load()"));
+    EME_LOG("MediaKeySession[%p,'%s'] Load() failed, uninitialized",
+      this, NS_ConvertUTF16toUTF8(aSessionId).get());
+    return promise.forget();
+  }
+
+  // 3.Let this object's uninitialized value be false.
+  mUninitialized = false;
+
+  // 4. If sessionId is the empty string, return a promise rejected with a newly created TypeError.
+  if (aSessionId.IsEmpty()) {
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+                         NS_LITERAL_CSTRING("Trying to load a session with empty session ID"));
+    // "The sessionId parameter is empty."
+    EME_LOG("MediaKeySession[%p,''] Load() failed, no sessionId", this);
+    return promise.forget();
+  }
+
+  // 5. If the result of running the Is persistent session type? algorithm
+  // on this object's session type is false, return a promise rejected with
+  // a newly created TypeError.
+  if (mSessionType == MediaKeySessionType::Temporary) {
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+                         NS_LITERAL_CSTRING("Trying to load() into a non-persistent session"));
+    EME_LOG("MediaKeySession[%p,''] Load() failed, can't load in a non-persistent session", this);
+    return promise.forget();
+  }
+
+  // Note: We don't support persistent sessions in any keysystem, so all calls
+  // to Load() should reject with a TypeError in the preceding check. Omitting
+  // implementing the rest of the specified MediaKeySession::Load() algorithm.
+
+  // We now know the sessionId being loaded into this session. Remove the
+  // session from its owning MediaKey's set of sessions awaiting a sessionId.
+  RefPtr<MediaKeySession> session(mKeys->GetPendingSession(Token()));
+  MOZ_ASSERT(session == this, "Session should be awaiting id on its own token");
+
+  // Associate with the known sessionId.
+  SetSessionId(aSessionId);
+
+  PromiseId pid = mKeys->StorePromise(promise);
+  mKeys->GetCDMProxy()->LoadSession(pid, aSessionId);
+
+  EME_LOG("MediaKeySession[%p,'%s'] Load() sent to CDM, promiseId=%d",
+    this, NS_ConvertUTF16toUTF8(mSessionId).get(), pid);
+
+  return promise.forget();
+}
+
+already_AddRefed<Promise>
+MediaKeySession::Update(const ArrayBufferViewOrArrayBuffer& aResponse, ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeySession.update")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  if (!IsCallable()) {
+    // If this object's callable value is false, return a promise rejected
+    // with a new DOMException whose name is InvalidStateError.
+    EME_LOG("MediaKeySession[%p,''] Update() called before sessionId set by CDM", this);
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+      NS_LITERAL_CSTRING("MediaKeySession.Update() called before sessionId set by CDM"));
+    return promise.forget();
+  }
+
+  nsTArray<uint8_t> data;
+  if (IsClosed() || !mKeys->GetCDMProxy()) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Session is closed or was not properly initialized"));
+    EME_LOG("MediaKeySession[%p,'%s'] Update() failed, session is closed or was not properly initialised.",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+  CopyArrayBufferViewOrArrayBufferData(aResponse, data);
+  if (data.IsEmpty()) {
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+      NS_LITERAL_CSTRING("Empty response buffer passed to MediaKeySession.update()"));
+    EME_LOG("MediaKeySession[%p,'%s'] Update() failed, empty response buffer",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+
+
+  // Convert response to base64 for easier logging.
+  // Note: UpdateSession() Move()s the data out of the array, so we have
+  // to copy it here.
+  nsAutoCString base64Response(ToBase64(data));
+
+  PromiseId pid = mKeys->StorePromise(promise);
+  mKeys->GetCDMProxy()->UpdateSession(mSessionId,
+                                      pid,
+                                      data);
+
+  EME_LOG("MediaKeySession[%p,'%s'] Update() sent to CDM, "
+          "promiseId=%d Response(base64)='%s'",
+           this,
+           NS_ConvertUTF16toUTF8(mSessionId).get(),
+           pid,
+           base64Response.get());
+
+  return promise.forget();
+}
+
+already_AddRefed<Promise>
+MediaKeySession::Close(ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeySession.close")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+  // 1. Let session be the associated MediaKeySession object.
+  // 2. If session is closed, return a resolved promise.
+  if (IsClosed()) {
+    EME_LOG("MediaKeySession[%p,'%s'] Close() already closed",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    promise->MaybeResolveWithUndefined();
+    return promise.forget();
+  }
+  // 3. If session's callable value is false, return a promise rejected
+  // with an InvalidStateError.
+  if (!IsCallable()) {
+    EME_LOG("MediaKeySession[%p,''] Close() called before sessionId set by CDM", this);
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+      NS_LITERAL_CSTRING("MediaKeySession.Close() called before sessionId set by CDM"));
+    return promise.forget();
+  }
+  if (!mKeys->GetCDMProxy()) {
+    EME_LOG("MediaKeySession[%p,'%s'] Close() null CDMProxy",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+      NS_LITERAL_CSTRING("MediaKeySession.Close() lost reference to CDM"));
+    return promise.forget();
+  }
+  // 4. Let promise be a new promise.
+  PromiseId pid = mKeys->StorePromise(promise);
+  // 5. Run the following steps in parallel:
+  // 5.1 Let cdm be the CDM instance represented by session's cdm instance value.
+  // 5.2 Use cdm to close the session associated with session.
+  mKeys->GetCDMProxy()->CloseSession(mSessionId, pid);
+
+  EME_LOG("MediaKeySession[%p,'%s'] Close() sent to CDM, promiseId=%d",
+          this, NS_ConvertUTF16toUTF8(mSessionId).get(), pid);
+
+  // Session Closed algorithm is run when CDM causes us to run OnSessionClosed().
+
+  // 6. Return promise.
+  return promise.forget();
+}
+
+void
+MediaKeySession::OnClosed()
+{
+  if (IsClosed()) {
+    return;
+  }
+  EME_LOG("MediaKeySession[%p,'%s'] session close operation complete.",
+          this, NS_ConvertUTF16toUTF8(mSessionId).get());
+  mIsClosed = true;
+  mKeys->OnSessionClosed(this);
+  mKeys = nullptr;
+  mClosed->MaybeResolveWithUndefined();
+}
+
+bool
+MediaKeySession::IsClosed() const
+{
+  return mIsClosed;
+}
+
+already_AddRefed<Promise>
+MediaKeySession::Remove(ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeySession.remove")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+  if (!IsCallable()) {
+    // If this object's callable value is false, return a promise rejected
+    // with a new DOMException whose name is InvalidStateError.
+    EME_LOG("MediaKeySession[%p,''] Remove() called before sessionId set by CDM", this);
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+      NS_LITERAL_CSTRING("MediaKeySession.Remove() called before sessionId set by CDM"));
+    return promise.forget();
+  }
+  if (mSessionType != MediaKeySessionType::Persistent_license) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_ACCESS_ERR,
+                         NS_LITERAL_CSTRING("Calling MediaKeySession.remove() on non-persistent session"));
+    // "The operation is not supported on session type sessions."
+    EME_LOG("MediaKeySession[%p,'%s'] Remove() failed, sesion not persisrtent.",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+  if (IsClosed() || !mKeys->GetCDMProxy()) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("MediaKeySesison.remove() called but session is not active"));
+    // "The session is closed."
+    EME_LOG("MediaKeySession[%p,'%s'] Remove() failed, already session closed.",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get());
+    return promise.forget();
+  }
+  PromiseId pid = mKeys->StorePromise(promise);
+  mKeys->GetCDMProxy()->RemoveSession(mSessionId, pid);
+  EME_LOG("MediaKeySession[%p,'%s'] Remove() sent to CDM, promiseId=%d.",
+          this, NS_ConvertUTF16toUTF8(mSessionId).get(), pid);
+
+  return promise.forget();
+}
+
+void
+MediaKeySession::DispatchKeyMessage(MediaKeyMessageType aMessageType,
+                                    const nsTArray<uint8_t>& aMessage)
+{
+  if (EME_LOG_ENABLED()) {
+    EME_LOG("MediaKeySession[%p,'%s'] DispatchKeyMessage() type=%s message(base64)='%s'",
+            this, NS_ConvertUTF16toUTF8(mSessionId).get(),
+            MediaKeyMessageTypeValues::strings[uint32_t(aMessageType)].value,
+            ToBase64(aMessage).get());
+  }
+
+  RefPtr<MediaKeyMessageEvent> event(
+    MediaKeyMessageEvent::Constructor(this, aMessageType, aMessage));
+  RefPtr<AsyncEventDispatcher> asyncDispatcher =
+    new AsyncEventDispatcher(this, event);
+  asyncDispatcher->PostDOMEvent();
+}
+
+void
+MediaKeySession::DispatchKeyError(uint32_t aSystemCode)
+{
+  EME_LOG("MediaKeySession[%p,'%s'] DispatchKeyError() systemCode=%u.",
+          this, NS_ConvertUTF16toUTF8(mSessionId).get(), aSystemCode);
+
+  RefPtr<MediaKeyError> event(new MediaKeyError(this, aSystemCode));
+  RefPtr<AsyncEventDispatcher> asyncDispatcher =
+    new AsyncEventDispatcher(this, event);
+  asyncDispatcher->PostDOMEvent();
+}
+
+void
+MediaKeySession::DispatchKeyStatusesChange()
+{
+  if (IsClosed()) {
+    return;
+  }
+
+  UpdateKeyStatusMap();
+
+  RefPtr<AsyncEventDispatcher> asyncDispatcher =
+    new AsyncEventDispatcher(this, NS_LITERAL_STRING("keystatuseschange"), false);
+  asyncDispatcher->PostDOMEvent();
+}
+
+uint32_t
+MediaKeySession::Token() const
+{
+  return mToken;
+}
+
+already_AddRefed<DetailedPromise>
+MediaKeySession::MakePromise(ErrorResult& aRv, const nsACString& aName)
+{
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
+  if (!global) {
+    NS_WARNING("Passed non-global to MediaKeys ctor!");
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return nullptr;
+  }
+  return DetailedPromise::Create(global, aRv, aName);
+}
+
+void
+MediaKeySession::SetExpiration(double aExpiration)
+{
+  EME_LOG("MediaKeySession[%p,'%s'] SetExpiry(%lf)",
+          this,
+          NS_ConvertUTF16toUTF8(mSessionId).get(),
+          aExpiration);
+  mExpiration = aExpiration;
+}
+
+EventHandlerNonNull*
+MediaKeySession::GetOnkeystatuseschange()
+{
+  return GetEventHandler(nsGkAtoms::onkeystatuseschange, EmptyString());
+}
+
+void
+MediaKeySession::SetOnkeystatuseschange(EventHandlerNonNull* aCallback)
+{
+  SetEventHandler(nsGkAtoms::onkeystatuseschange, EmptyString(), aCallback);
+}
+
+EventHandlerNonNull*
+MediaKeySession::GetOnmessage()
+{
+  return GetEventHandler(nsGkAtoms::onmessage, EmptyString());
+}
+
+void
+MediaKeySession::SetOnmessage(EventHandlerNonNull* aCallback)
+{
+  SetEventHandler(nsGkAtoms::onmessage, EmptyString(), aCallback);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeySession.h b/dom/media/eme/MediaKeySession.h
new file mode 100644
index 0000000000..40481df996
--- /dev/null
+++ b/dom/media/eme/MediaKeySession.h
@@ -0,0 +1,137 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeySession_h
+#define mozilla_dom_MediaKeySession_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/DOMEventTargetHelper.h"
+#include "nsCOMPtr.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/dom/Date.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/DetailedPromise.h"
+#include "mozilla/dom/MediaKeySessionBinding.h"
+#include "mozilla/dom/MediaKeysBinding.h"
+#include "mozilla/dom/MediaKeyMessageEventBinding.h"
+
+struct JSContext;
+
+namespace mozilla {
+namespace dom {
+
+class ArrayBufferViewOrArrayBuffer;
+class MediaKeyError;
+class MediaKeyStatusMap;
+
+class MediaKeySession final : public DOMEventTargetHelper
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaKeySession,
+                                           DOMEventTargetHelper)
+public:
+  MediaKeySession(JSContext* aCx,
+                  nsPIDOMWindowInner* aParent,
+                  MediaKeys* aKeys,
+                  const nsAString& aKeySystem,
+                  MediaKeySessionType aSessionType,
+                  ErrorResult& aRv);
+
+  void SetSessionId(const nsAString& aSessionId);
+
+  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  // Mark this as resultNotAddRefed to return raw pointers
+  MediaKeyError* GetError() const;
+
+  MediaKeyStatusMap* KeyStatuses() const;
+
+  void GetKeySystem(nsString& aRetval) const;
+
+  void GetSessionId(nsString& aRetval) const;
+
+  const nsString& GetSessionId() const;
+
+  // Number of ms since epoch at which expiration occurs, or NaN if unknown.
+  // TODO: The type of this attribute is still under contention.
+  // https://www.w3.org/Bugs/Public/show_bug.cgi?id=25902
+  double Expiration() const;
+
+  Promise* Closed() const;
+
+  already_AddRefed<Promise> GenerateRequest(const nsAString& aInitDataType,
+                                            const ArrayBufferViewOrArrayBuffer& aInitData,
+                                            ErrorResult& aRv);
+
+  already_AddRefed<Promise> Load(const nsAString& aSessionId,
+                                 ErrorResult& aRv);
+
+  already_AddRefed<Promise> Update(const ArrayBufferViewOrArrayBuffer& response,
+                                   ErrorResult& aRv);
+
+  already_AddRefed<Promise> Close(ErrorResult& aRv);
+
+  already_AddRefed<Promise> Remove(ErrorResult& aRv);
+
+  void DispatchKeyMessage(MediaKeyMessageType aMessageType,
+                          const nsTArray<uint8_t>& aMessage);
+
+  void DispatchKeyError(uint32_t system_code);
+
+  void DispatchKeyStatusesChange();
+
+  void OnClosed();
+
+  bool IsClosed() const;
+
+  void SetExpiration(double aExpiry);
+
+  mozilla::dom::EventHandlerNonNull* GetOnkeystatuseschange();
+  void SetOnkeystatuseschange(mozilla::dom::EventHandlerNonNull* aCallback);
+
+  mozilla::dom::EventHandlerNonNull* GetOnmessage();
+  void SetOnmessage(mozilla::dom::EventHandlerNonNull* aCallback);
+
+  // Process-unique identifier.
+  uint32_t Token() const;
+
+private:
+  ~MediaKeySession();
+
+  void UpdateKeyStatusMap();
+
+  bool IsCallable() const {
+    // The EME spec sets the "callable value" to true whenever the CDM sets
+    // the sessionId. When the session is initialized, sessionId is empty and
+    // callable is thus false.
+    return !mSessionId.IsEmpty();
+  }
+
+  already_AddRefed<DetailedPromise> MakePromise(ErrorResult& aRv,
+                                                const nsACString& aName);
+
+  RefPtr<DetailedPromise> mClosed;
+
+  RefPtr<MediaKeyError> mMediaKeyError;
+  RefPtr<MediaKeys> mKeys;
+  const nsString mKeySystem;
+  nsString mSessionId;
+  const MediaKeySessionType mSessionType;
+  const uint32_t mToken;
+  bool mIsClosed;
+  bool mUninitialized;
+  RefPtr<MediaKeyStatusMap> mKeyStatusMap;
+  double mExpiration;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif
diff --git a/dom/media/eme/MediaKeyStatusMap.cpp b/dom/media/eme/MediaKeyStatusMap.cpp
new file mode 100644
index 0000000000..5af6ff5358
--- /dev/null
+++ b/dom/media/eme/MediaKeyStatusMap.cpp
@@ -0,0 +1,121 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/MediaKeyStatusMap.h"
+#include "nsPIDOMWindow.h"
+#include "mozilla/dom/UnionTypes.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "mozilla/EMEUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeyStatusMap)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeyStatusMap)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeyStatusMap)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeyStatusMap, mParent)
+
+MediaKeyStatusMap::MediaKeyStatusMap(nsPIDOMWindowInner* aParent)
+  : mParent(aParent)
+{
+}
+
+MediaKeyStatusMap::~MediaKeyStatusMap()
+{
+}
+
+JSObject*
+MediaKeyStatusMap::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeyStatusMapBinding::Wrap(aCx, this, aGivenProto);
+}
+
+nsPIDOMWindowInner*
+MediaKeyStatusMap::GetParentObject() const
+{
+  return mParent;
+}
+
+void
+MediaKeyStatusMap::Get(JSContext* aCx,
+                       const ArrayBufferViewOrArrayBuffer& aKey,
+                       JS::MutableHandle<JS::Value> aOutValue,
+                       ErrorResult& aOutRv) const
+{
+  ArrayData keyId = GetArrayBufferViewOrArrayBufferData(aKey);
+  if (!keyId.IsValid()) {
+    aOutValue.setUndefined();
+    return;
+  }
+  for (const KeyStatus& status : mStatuses) {
+    if (keyId == status.mKeyId) {
+      bool ok = ToJSValue(aCx, status.mStatus, aOutValue);

+      if (!ok) {

+        aOutRv.NoteJSContextException(aCx);

+      }

+      return;
+    }
+  }
+  aOutValue.setUndefined();
+}
+
+bool
+MediaKeyStatusMap::Has(const ArrayBufferViewOrArrayBuffer& aKey) const
+{
+  ArrayData keyId = GetArrayBufferViewOrArrayBufferData(aKey);
+  if (!keyId.IsValid()) {
+    return false;
+  }
+
+  for (const KeyStatus& status : mStatuses) {
+    if (keyId == status.mKeyId) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+uint32_t
+MediaKeyStatusMap::GetIterableLength() const
+{
+  return mStatuses.Length();
+}
+
+TypedArrayCreator<ArrayBuffer>
+MediaKeyStatusMap::GetKeyAtIndex(uint32_t aIndex) const
+{
+  MOZ_ASSERT(aIndex < GetIterableLength());
+  return TypedArrayCreator<ArrayBuffer>(mStatuses[aIndex].mKeyId);
+}
+
+MediaKeyStatus
+MediaKeyStatusMap::GetValueAtIndex(uint32_t aIndex) const
+{
+  MOZ_ASSERT(aIndex < GetIterableLength());
+  return mStatuses[aIndex].mStatus;
+}
+
+uint32_t
+MediaKeyStatusMap::Size() const
+{
+  return mStatuses.Length();
+}
+
+void
+MediaKeyStatusMap::Update(const nsTArray<CDMCaps::KeyStatus>& aKeys)
+{
+  mStatuses.Clear();
+  for (const auto& key : aKeys) {
+    mStatuses.InsertElementSorted(KeyStatus(key.mId, key.mStatus));
+  }
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeyStatusMap.h b/dom/media/eme/MediaKeyStatusMap.h
new file mode 100644
index 0000000000..396ae500ef
--- /dev/null
+++ b/dom/media/eme/MediaKeyStatusMap.h
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeyStatuses_h
+#define mozilla_dom_MediaKeyStatuses_h
+
+#include "mozilla/ErrorResult.h"
+#include "mozilla/Attributes.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/dom/MediaKeyStatusMapBinding.h"
+#include "mozilla/CDMCaps.h"
+
+class nsPIDOMWindowInner;
+
+namespace mozilla {
+namespace dom {
+
+class ArrayBufferViewOrArrayBuffer;
+
+// The MediaKeyStatusMap WebIDL interface; maps a keyId to its status.
+// Note that the underlying "map" is stored in an array, since we assume
+// that a MediaKeySession won't have many key statuses to report.
+class MediaKeyStatusMap final : public nsISupports,
+                                public nsWrapperCache
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaKeyStatusMap)
+
+public:
+  explicit MediaKeyStatusMap(nsPIDOMWindowInner* aParent);
+
+protected:
+  ~MediaKeyStatusMap();
+
+public:
+  nsPIDOMWindowInner* GetParentObject() const;
+
+  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  void Get(JSContext* aCx,
+           const ArrayBufferViewOrArrayBuffer& aKey,
+           JS::MutableHandle<JS::Value> aOutValue,
+           ErrorResult& aOutRv) const;
+  bool Has(const ArrayBufferViewOrArrayBuffer& aKey) const;
+  uint32_t Size() const;
+
+  uint32_t GetIterableLength() const;
+  TypedArrayCreator<ArrayBuffer> GetKeyAtIndex(uint32_t aIndex) const;
+  MediaKeyStatus GetValueAtIndex(uint32_t aIndex) const;
+
+  void Update(const nsTArray<CDMCaps::KeyStatus>& keys);
+
+private:
+
+  nsCOMPtr<nsPIDOMWindowInner> mParent;
+
+  struct KeyStatus {
+    KeyStatus(const nsTArray<uint8_t>& aKeyId,
+              MediaKeyStatus aStatus)
+      : mKeyId(aKeyId)
+      , mStatus(aStatus)
+    {
+    }
+    bool operator== (const KeyStatus& aOther) const {
+      return aOther.mKeyId == mKeyId;
+    }
+    bool operator<(const KeyStatus& aOther) const {
+      // Copy chromium and compare keys' bytes.
+      // Update once https://github.com/w3c/encrypted-media/issues/69
+      // is resolved.
+      const nsTArray<uint8_t>& other = aOther.mKeyId;
+      const nsTArray<uint8_t>& self = mKeyId;
+      size_t length = std::min<size_t>(other.Length(), self.Length());
+      int cmp = memcmp(self.Elements(), other.Elements(), length);
+      if (cmp != 0) {
+        return cmp < 0;
+      }
+      return self.Length() <= other.Length();
+    }
+    nsTArray<uint8_t> mKeyId;
+    MediaKeyStatus mStatus;
+  };
+
+  nsTArray<KeyStatus> mStatuses;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif
diff --git a/dom/media/eme/MediaKeySystemAccess.cpp b/dom/media/eme/MediaKeySystemAccess.cpp
new file mode 100644
index 0000000000..7007d3a03d
--- /dev/null
+++ b/dom/media/eme/MediaKeySystemAccess.cpp
@@ -0,0 +1,1135 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/MediaKeySystemAccess.h"
+#include "mozilla/dom/MediaKeySystemAccessBinding.h"
+#include "mozilla/Preferences.h"
+#include "MediaPrefs.h"
+#include "nsContentTypeParser.h"
+#ifdef MOZ_FMP4
+#include "MP4Decoder.h"
+#endif
+#ifdef XP_WIN
+#include "mozilla/WindowsVersion.h"
+#include "WMFDecoderModule.h"
+#endif
+#include "nsContentCID.h"
+#include "nsServiceManagerUtils.h"
+#include "mozIGeckoMediaPluginService.h"
+#include "VideoUtils.h"
+#include "mozilla/Services.h"
+#include "nsIObserverService.h"
+#include "mozilla/EMEUtils.h"
+#include "GMPUtils.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsXULAppAPI.h"
+#include "gmp-audio-decode.h"
+#include "gmp-video-decode.h"
+#include "DecoderDoctorDiagnostics.h"
+#include "WebMDecoder.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "nsUnicharUtils.h"
+#include "mozilla/dom/MediaSource.h"
+#ifdef MOZ_WIDGET_ANDROID
+#include "FennecJNIWrappers.h"
+#endif
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeySystemAccess,
+                                      mParent)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeySystemAccess)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeySystemAccess)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeySystemAccess)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+MediaKeySystemAccess::MediaKeySystemAccess(nsPIDOMWindowInner* aParent,
+                                           const nsAString& aKeySystem,
+                                           const MediaKeySystemConfiguration& aConfig)
+  : mParent(aParent)
+  , mKeySystem(aKeySystem)
+  , mConfig(aConfig)
+{
+}
+
+MediaKeySystemAccess::~MediaKeySystemAccess()
+{
+}
+
+JSObject*
+MediaKeySystemAccess::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeySystemAccessBinding::Wrap(aCx, this, aGivenProto);
+}
+
+nsPIDOMWindowInner*
+MediaKeySystemAccess::GetParentObject() const
+{
+  return mParent;
+}
+
+void
+MediaKeySystemAccess::GetKeySystem(nsString& aOutKeySystem) const
+{
+  aOutKeySystem.Assign(mKeySystem);
+}
+
+void
+MediaKeySystemAccess::GetConfiguration(MediaKeySystemConfiguration& aConfig)
+{
+  aConfig = mConfig;
+}
+
+already_AddRefed<Promise>
+MediaKeySystemAccess::CreateMediaKeys(ErrorResult& aRv)
+{
+  RefPtr<MediaKeys> keys(new MediaKeys(mParent,
+                                       mKeySystem,
+                                       mConfig));
+  return keys->Init(aRv);
+}
+
+static bool
+HavePluginForKeySystem(const nsCString& aKeySystem)
+{
+  bool havePlugin = HaveGMPFor(NS_LITERAL_CSTRING(GMP_API_DECRYPTOR),
+                               { aKeySystem });
+#ifdef MOZ_WIDGET_ANDROID
+  // Check if we can use MediaDrm for this keysystem.
+  if (!havePlugin) {
+    havePlugin = mozilla::java::MediaDrmProxy::IsSchemeSupported(aKeySystem);
+  }
+#endif
+  return havePlugin;
+}
+
+static MediaKeySystemStatus
+EnsureCDMInstalled(const nsAString& aKeySystem,
+                    nsACString& aOutMessage)
+{
+  if (!HavePluginForKeySystem(NS_ConvertUTF16toUTF8(aKeySystem))) {
+    aOutMessage = NS_LITERAL_CSTRING("CDM is not installed");
+    return MediaKeySystemStatus::Cdm_not_installed;
+  }
+
+  return MediaKeySystemStatus::Available;
+}
+
+/* static */
+MediaKeySystemStatus
+MediaKeySystemAccess::GetKeySystemStatus(const nsAString& aKeySystem,
+                                         nsACString& aOutMessage)
+{
+  MOZ_ASSERT(MediaPrefs::EMEEnabled() || IsClearkeyKeySystem(aKeySystem));
+
+  if (IsClearkeyKeySystem(aKeySystem)) {
+    return EnsureCDMInstalled(aKeySystem, aOutMessage);
+  }
+
+  if (Preferences::GetBool("media.gmp-eme-adobe.visible", false)) {
+    if (IsPrimetimeKeySystem(aKeySystem)) {
+      if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
+        aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
+        return MediaKeySystemStatus::Cdm_disabled;
+      }
+#ifdef XP_WIN
+      // Win Vista and later only.
+      if (!IsVistaOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Adobe EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
+#endif
+      return EnsureCDMInstalled(aKeySystem, aOutMessage);
+    }
+  }
+
+  if (IsWidevineKeySystem(aKeySystem)) {
+    if (Preferences::GetBool("media.gmp-widevinecdm.visible", false)) {
+#ifdef XP_WIN
+      // Win Vista and later only.
+      if (!IsVistaOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Widevine EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
+#endif
+      if (!Preferences::GetBool("media.gmp-widevinecdm.enabled", false)) {
+        aOutMessage = NS_LITERAL_CSTRING("Widevine EME disabled");
+        return MediaKeySystemStatus::Cdm_disabled;
+      }
+      return EnsureCDMInstalled(aKeySystem, aOutMessage);
+#ifdef MOZ_WIDGET_ANDROID
+    } else if (Preferences::GetBool("media.mediadrm-widevinecdm.visible", false)) {
+        nsCString keySystem = NS_ConvertUTF16toUTF8(aKeySystem);
+        bool supported = mozilla::java::MediaDrmProxy::IsSchemeSupported(keySystem);
+        if (!supported) {
+          aOutMessage = NS_LITERAL_CSTRING("Widevine CDM is not available");
+          return MediaKeySystemStatus::Cdm_not_installed;
+        }
+        return MediaKeySystemStatus::Available;
+#endif
+    }
+  }
+
+  return MediaKeySystemStatus::Cdm_not_supported;
+}
+
+typedef nsCString EMECodecString;
+
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_AAC, "aac");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_OPUS, "opus");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_VORBIS, "vorbis");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_H264, "h264");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_VP8, "vp8");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_VP9, "vp9");
+
+EMECodecString
+ToEMEAPICodecString(const nsString& aCodec)
+{
+  if (IsAACCodecString(aCodec)) {
+    return EME_CODEC_AAC;
+  }
+  if (aCodec.EqualsLiteral("opus")) {
+    return EME_CODEC_OPUS;
+  }
+  if (aCodec.EqualsLiteral("vorbis")) {
+    return EME_CODEC_VORBIS;
+  }
+  if (IsH264CodecString(aCodec)) {
+    return EME_CODEC_H264;
+  }
+  if (IsVP8CodecString(aCodec)) {
+    return EME_CODEC_VP8;
+  }
+  if (IsVP9CodecString(aCodec)) {
+    return EME_CODEC_VP9;
+  }
+  return EmptyCString();
+}
+
+// A codec can be decrypted-and-decoded by the CDM, or only decrypted
+// by the CDM and decoded by Gecko. Not both.
+struct KeySystemContainerSupport
+{
+  bool IsSupported() const
+  {
+    return !mCodecsDecoded.IsEmpty() || !mCodecsDecrypted.IsEmpty();
+  }
+
+  // CDM decrypts and decodes using a DRM robust decoder, and passes decoded
+  // samples back to Gecko for rendering.
+  bool DecryptsAndDecodes(EMECodecString aCodec) const
+  {
+    return mCodecsDecoded.Contains(aCodec);
+  }
+
+  // CDM decrypts and passes the decrypted samples back to Gecko for decoding.
+  bool Decrypts(EMECodecString aCodec) const
+  {
+    return mCodecsDecrypted.Contains(aCodec);
+  }
+
+  void SetCanDecryptAndDecode(EMECodecString aCodec)
+  {
+    // Can't both decrypt and decrypt-and-decode a codec.
+    MOZ_ASSERT(!Decrypts(aCodec));
+    // Prevent duplicates.
+    MOZ_ASSERT(!DecryptsAndDecodes(aCodec));
+    mCodecsDecoded.AppendElement(aCodec);
+  }
+
+  void SetCanDecrypt(EMECodecString aCodec)
+  {
+    // Prevent duplicates.
+    MOZ_ASSERT(!Decrypts(aCodec));
+    // Can't both decrypt and decrypt-and-decode a codec.
+    MOZ_ASSERT(!DecryptsAndDecodes(aCodec));
+    mCodecsDecrypted.AppendElement(aCodec);
+  }
+
+private:
+  nsTArray<EMECodecString> mCodecsDecoded;
+  nsTArray<EMECodecString> mCodecsDecrypted;
+};
+
+enum class KeySystemFeatureSupport
+{
+  Prohibited = 1,
+  Requestable = 2,
+  Required = 3,
+};
+
+struct KeySystemConfig
+{
+  nsString mKeySystem;
+  nsTArray<nsString> mInitDataTypes;
+  KeySystemFeatureSupport mPersistentState = KeySystemFeatureSupport::Prohibited;
+  KeySystemFeatureSupport mDistinctiveIdentifier = KeySystemFeatureSupport::Prohibited;
+  nsTArray<MediaKeySessionType> mSessionTypes;
+  nsTArray<nsString> mVideoRobustness;
+  nsTArray<nsString> mAudioRobustness;
+  KeySystemContainerSupport mMP4;
+  KeySystemContainerSupport mWebM;
+};
+
+static nsTArray<KeySystemConfig>
+GetSupportedKeySystems()
+{
+  nsTArray<KeySystemConfig> keySystemConfigs;
+
+  {
+    if (HavePluginForKeySystem(kEMEKeySystemClearkey)) {
+      KeySystemConfig clearkey;
+      clearkey.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemClearkey);
+      clearkey.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
+      clearkey.mInitDataTypes.AppendElement(NS_LITERAL_STRING("keyids"));
+      clearkey.mInitDataTypes.AppendElement(NS_LITERAL_STRING("webm"));
+      clearkey.mPersistentState = KeySystemFeatureSupport::Requestable;
+      clearkey.mDistinctiveIdentifier = KeySystemFeatureSupport::Prohibited;
+      clearkey.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
+      if (MediaPrefs::ClearKeyPersistentLicenseEnabled()) {
+        clearkey.mSessionTypes.AppendElement(MediaKeySessionType::Persistent_license);
+      }
+#if defined(XP_WIN)
+      // Clearkey CDM uses WMF decoders on Windows.
+      if (WMFDecoderModule::HasAAC()) {
+        clearkey.mMP4.SetCanDecryptAndDecode(EME_CODEC_AAC);
+      } else {
+        clearkey.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+      }
+      if (WMFDecoderModule::HasH264()) {
+        clearkey.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
+      } else {
+        clearkey.mMP4.SetCanDecrypt(EME_CODEC_H264);
+      }
+#else
+      clearkey.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+      clearkey.mMP4.SetCanDecrypt(EME_CODEC_H264);
+#endif
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_VORBIS);
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_OPUS);
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_VP8);
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_VP9);
+      keySystemConfigs.AppendElement(Move(clearkey));
+    }
+  }
+  {
+    if (HavePluginForKeySystem(kEMEKeySystemWidevine)) {
+      KeySystemConfig widevine;
+      widevine.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemWidevine);
+      widevine.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
+      widevine.mInitDataTypes.AppendElement(NS_LITERAL_STRING("keyids"));
+      widevine.mInitDataTypes.AppendElement(NS_LITERAL_STRING("webm"));
+      widevine.mPersistentState = KeySystemFeatureSupport::Requestable;
+      widevine.mDistinctiveIdentifier = KeySystemFeatureSupport::Prohibited;
+      widevine.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
+#ifdef MOZ_WIDGET_ANDROID
+      widevine.mSessionTypes.AppendElement(MediaKeySessionType::Persistent_license);
+#endif
+      widevine.mAudioRobustness.AppendElement(NS_LITERAL_STRING("SW_SECURE_CRYPTO"));
+      widevine.mVideoRobustness.AppendElement(NS_LITERAL_STRING("SW_SECURE_DECODE"));
+#if defined(XP_WIN)
+      // Widevine CDM doesn't include an AAC decoder. So if WMF can't
+      // decode AAC, and a codec wasn't specified, be conservative
+      // and reject the MediaKeys request, since our policy is to prevent
+      //  the Adobe GMP's unencrypted AAC decoding path being used to
+      // decode content decrypted by the Widevine CDM.
+      if (WMFDecoderModule::HasAAC()) {
+        widevine.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+      }
+#elif !defined(MOZ_WIDGET_ANDROID)
+      widevine.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+#endif
+
+#if defined(MOZ_WIDGET_ANDROID)
+      using namespace mozilla::java;
+      // MediaDrm.isCryptoSchemeSupported only allows passing
+      // "video/mp4" or "video/webm" for mimetype string.
+      // See https://developer.android.com/reference/android/media/MediaDrm.html#isCryptoSchemeSupported(java.util.UUID, java.lang.String)
+      // for more detail.
+      typedef struct {
+        const nsCString& mMimeType;
+        const nsCString& mEMECodecType;
+        const char16_t* mCodecType;
+        KeySystemContainerSupport* mSupportType;
+      } DataForValidation;
+
+      DataForValidation validationList[] = {
+        { nsCString("video/mp4"), EME_CODEC_H264, MediaDrmProxy::AVC, &widevine.mMP4 },
+        { nsCString("audio/mp4"), EME_CODEC_AAC, MediaDrmProxy::AAC, &widevine.mMP4 },
+        { nsCString("video/webm"), EME_CODEC_VP8, MediaDrmProxy::VP8, &widevine.mWebM },
+        { nsCString("video/webm"), EME_CODEC_VP9, MediaDrmProxy::VP9, &widevine.mWebM},
+        { nsCString("audio/webm"), EME_CODEC_VORBIS, MediaDrmProxy::VORBIS, &widevine.mWebM},
+        { nsCString("audio/webm"), EME_CODEC_OPUS, MediaDrmProxy::OPUS, &widevine.mWebM},
+      };
+
+      for (const auto& data: validationList) {
+        if (MediaDrmProxy::IsCryptoSchemeSupported(kEMEKeySystemWidevine,
+                                                   data.mMimeType)) {
+          if (MediaDrmProxy::CanDecode(data.mCodecType)) {
+            data.mSupportType->SetCanDecryptAndDecode(data.mEMECodecType);
+          } else {
+            data.mSupportType->SetCanDecrypt(data.mEMECodecType);
+          }
+        }
+      }
+#else
+      widevine.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
+      widevine.mWebM.SetCanDecrypt(EME_CODEC_VORBIS);
+      widevine.mWebM.SetCanDecrypt(EME_CODEC_OPUS);
+      widevine.mWebM.SetCanDecryptAndDecode(EME_CODEC_VP8);
+      widevine.mWebM.SetCanDecryptAndDecode(EME_CODEC_VP9);
+#endif
+      keySystemConfigs.AppendElement(Move(widevine));
+    }
+  }
+  {
+    if (HavePluginForKeySystem(kEMEKeySystemPrimetime)) {
+      KeySystemConfig primetime;
+      primetime.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemPrimetime);
+      primetime.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
+      primetime.mPersistentState = KeySystemFeatureSupport::Required;
+      primetime.mDistinctiveIdentifier = KeySystemFeatureSupport::Required;
+      primetime.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
+      primetime.mMP4.SetCanDecryptAndDecode(EME_CODEC_AAC);
+      primetime.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
+      keySystemConfigs.AppendElement(Move(primetime));
+    }
+  }
+
+  return keySystemConfigs;
+}
+
+static bool
+GetKeySystemConfig(const nsAString& aKeySystem, KeySystemConfig& aOutKeySystemConfig)
+{
+  for (auto&& config : GetSupportedKeySystems()) {
+    if (config.mKeySystem.Equals(aKeySystem)) {
+      aOutKeySystemConfig = mozilla::Move(config);
+      return true;
+    }
+  }
+  // No matching key system found.
+  return false;
+}
+
+/* static */
+bool
+MediaKeySystemAccess::KeySystemSupportsInitDataType(const nsAString& aKeySystem,
+                                                    const nsAString& aInitDataType)
+{
+  KeySystemConfig implementation;
+  return GetKeySystemConfig(aKeySystem, implementation) &&
+         implementation.mInitDataTypes.Contains(aInitDataType);
+}
+
+enum CodecType
+{
+  Audio,
+  Video,
+  Invalid
+};
+
+static bool
+CanDecryptAndDecode(const nsString& aKeySystem,
+                    const nsString& aContentType,
+                    CodecType aCodecType,
+                    const KeySystemContainerSupport& aContainerSupport,
+                    const nsTArray<EMECodecString>& aCodecs,
+                    DecoderDoctorDiagnostics* aDiagnostics)
+{
+  MOZ_ASSERT(aCodecType != Invalid);
+  for (const EMECodecString& codec : aCodecs) {
+    MOZ_ASSERT(!codec.IsEmpty());
+
+    if (aContainerSupport.DecryptsAndDecodes(codec)) {
+      // GMP can decrypt-and-decode this codec.
+      continue;
+    }
+
+    if (aContainerSupport.Decrypts(codec) &&
+        NS_SUCCEEDED(MediaSource::IsTypeSupported(aContentType, aDiagnostics))) {
+      // GMP can decrypt and is allowed to return compressed samples to
+      // Gecko to decode, and Gecko has a decoder.
+      continue;
+    }
+
+    // Neither the GMP nor Gecko can both decrypt and decode. We don't
+    // support this codec.
+
+#if defined(XP_WIN)
+    // Widevine CDM doesn't include an AAC decoder. So if WMF can't
+    // decode AAC, and a codec wasn't specified, be conservative
+    // and reject the MediaKeys request, since our policy is to prevent
+    //  the Adobe GMP's unencrypted AAC decoding path being used to
+    // decode content decrypted by the Widevine CDM.
+    if (codec == EME_CODEC_AAC &&
+        IsWidevineKeySystem(aKeySystem) &&
+        !WMFDecoderModule::HasAAC()) {
+      if (aDiagnostics) {
+        aDiagnostics->SetKeySystemIssue(
+          DecoderDoctorDiagnostics::eWidevineWithNoWMF);
+      }
+    }
+#endif
+    return false;
+  }
+  return true;
+}
+
+static bool
+ToSessionType(const nsAString& aSessionType, MediaKeySessionType& aOutType)
+{
+  using MediaKeySessionTypeValues::strings;
+  const char* temporary =
+    strings[static_cast<uint32_t>(MediaKeySessionType::Temporary)].value;
+  if (aSessionType.EqualsASCII(temporary)) {
+    aOutType = MediaKeySessionType::Temporary;
+    return true;
+  }
+  const char* persistentLicense =
+    strings[static_cast<uint32_t>(MediaKeySessionType::Persistent_license)].value;
+  if (aSessionType.EqualsASCII(persistentLicense)) {
+    aOutType = MediaKeySessionType::Persistent_license;
+    return true;
+  }
+  return false;
+}
+
+// 5.2.1 Is persistent session type?
+static bool
+IsPersistentSessionType(MediaKeySessionType aSessionType)
+{
+  return aSessionType == MediaKeySessionType::Persistent_license;
+}
+
+CodecType
+GetMajorType(const nsAString& aContentType)
+{
+  if (CaseInsensitiveFindInReadable(NS_LITERAL_STRING("audio/"), aContentType)) {
+    return Audio;
+  }
+  if (CaseInsensitiveFindInReadable(NS_LITERAL_STRING("video/"), aContentType)) {
+    return Video;
+  }
+  return Invalid;
+}
+
+static CodecType
+GetCodecType(const EMECodecString& aCodec)
+{
+  if (aCodec.Equals(EME_CODEC_AAC) ||
+      aCodec.Equals(EME_CODEC_OPUS) ||
+      aCodec.Equals(EME_CODEC_VORBIS)) {
+    return Audio;
+  }
+  if (aCodec.Equals(EME_CODEC_H264) ||
+      aCodec.Equals(EME_CODEC_VP8) ||
+      aCodec.Equals(EME_CODEC_VP9)) {
+    return Video;
+  }
+  return Invalid;
+}
+
+static bool
+AllCodecsOfType(const nsTArray<EMECodecString>& aCodecs, const CodecType aCodecType)
+{
+  for (const EMECodecString& codec : aCodecs) {
+    if (GetCodecType(codec) != aCodecType) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static bool
+IsParameterUnrecognized(const nsAString& aContentType)
+{
+  nsAutoString contentType(aContentType);
+  contentType.StripWhitespace();
+
+  nsTArray<nsString> params;
+  nsAString::const_iterator start, end, semicolon, equalSign;
+  contentType.BeginReading(start);
+  contentType.EndReading(end);
+  semicolon = start;
+  // Find any substring between ';' & '='.
+  while (semicolon != end) {
+    if (FindCharInReadable(';', semicolon, end)) {
+      equalSign = ++semicolon;
+      if (FindCharInReadable('=', equalSign, end)) {
+        params.AppendElement(Substring(semicolon, equalSign));
+        semicolon = equalSign;
+      }
+    }
+  }
+
+  for (auto param : params) {
+    if (!param.LowerCaseEqualsLiteral("codecs") &&
+        !param.LowerCaseEqualsLiteral("profiles")) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// 3.1.2.3 Get Supported Capabilities for Audio/Video Type
+static Sequence<MediaKeySystemMediaCapability>
+GetSupportedCapabilities(const CodecType aCodecType,
+                         const nsTArray<MediaKeySystemMediaCapability>& aRequestedCapabilities,
+                         const MediaKeySystemConfiguration& aPartialConfig,
+                         const KeySystemConfig& aKeySystem,
+                         DecoderDoctorDiagnostics* aDiagnostics)
+{
+  // Let local accumulated configuration be a local copy of partial configuration.
+  // (Note: It's not necessary for us to maintain a local copy, as we don't need
+  // to test whether capabilites from previous calls to this algorithm work with
+  // the capabilities currently being considered in this call. )
+
+  // Let supported media capabilities be an empty sequence of
+  // MediaKeySystemMediaCapability dictionaries.
+  Sequence<MediaKeySystemMediaCapability> supportedCapabilities;
+
+  // For each requested media capability in requested media capabilities:
+  for (const MediaKeySystemMediaCapability& capabilities : aRequestedCapabilities) {
+    // Let content type be requested media capability's contentType member.
+    const nsString& contentType = capabilities.mContentType;
+    // Let robustness be requested media capability's robustness member.
+    const nsString& robustness = capabilities.mRobustness;
+    // If content type is the empty string, return null.
+    if (contentType.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') rejected; "
+              "audio or video capability has empty contentType.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      return Sequence<MediaKeySystemMediaCapability>();
+    }
+    // If content type is an invalid or unrecognized MIME type, continue
+    // to the next iteration.
+    nsAutoString container;
+    nsTArray<nsString> codecStrings;
+    if (!ParseMIMETypeString(contentType, container, codecStrings)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "failed to parse contentType as MIME type.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    bool invalid = false;
+    nsTArray<EMECodecString> codecs;
+    for (const nsString& codecString : codecStrings) {
+      EMECodecString emeCodec = ToEMEAPICodecString(codecString);
+      if (emeCodec.IsEmpty()) {
+        invalid = true;
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "'%s' is an invalid codec string.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get(),
+                NS_ConvertUTF16toUTF8(codecString).get());
+        break;
+      }
+      codecs.AppendElement(emeCodec);
+    }
+    if (invalid) {
+      continue;
+    }
+
+    // If the user agent does not support container, continue to the next iteration.
+    // The case-sensitivity of string comparisons is determined by the appropriate RFC.
+    // (Note: Per RFC 6838 [RFC6838], "Both top-level type and subtype names are
+    // case-insensitive."'. We're using nsContentTypeParser and that is
+    // case-insensitive and converts all its parameter outputs to lower case.)
+    NS_ConvertUTF16toUTF8 container_utf8(container);
+    const bool isMP4 = DecoderTraits::IsMP4TypeAndEnabled(container_utf8, aDiagnostics);
+    if (isMP4 && !aKeySystem.mMP4.IsSupported()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "MP4 requested but unsupported.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    const bool isWebM = DecoderTraits::IsWebMTypeAndEnabled(container_utf8);
+    if (isWebM && !aKeySystem.mWebM.IsSupported()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "WebM requested but unsupported.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    if (!isMP4 && !isWebM) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "Unsupported or unrecognized container requested.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+
+    // Let parameters be the RFC 6381[RFC6381] parameters, if any, specified by
+    // content type.
+    // If the user agent does not recognize one or more parameters, continue to
+    // the next iteration.
+    if (IsParameterUnrecognized(contentType)) {
+      continue;
+    }
+
+    // Let media types be the set of codecs and codec constraints specified by
+    // parameters. The case-sensitivity of string comparisons is determined by
+    // the appropriate RFC or other specification.
+    // (Note: codecs array is 'parameter').
+
+    // If media types is empty:
+    if (codecs.IsEmpty()) {
+      // If container normatively implies a specific set of codecs and codec constraints:
+      // Let parameters be that set.
+      if (isMP4) {
+        if (aCodecType == Audio) {
+          codecs.AppendElement(EME_CODEC_AAC);
+        } else if (aCodecType == Video) {
+          codecs.AppendElement(EME_CODEC_H264);
+        }
+      } else if (isWebM) {
+        if (aCodecType == Audio) {
+          codecs.AppendElement(EME_CODEC_VORBIS);
+        } else if (aCodecType == Video) {
+          codecs.AppendElement(EME_CODEC_VP8);
+        }
+      }
+      // Otherwise: Continue to the next iteration.
+      // (Note: all containers we support have implied codecs, so don't continue here.)
+    }
+
+    // If content type is not strictly a audio/video type, continue to the next iteration.
+    const auto majorType = GetMajorType(container);
+    if (majorType == Invalid) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "MIME type is not an audio or video MIME type.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    if (majorType != aCodecType || !AllCodecsOfType(codecs, aCodecType)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "MIME type mixes audio codecs in video capabilities "
+              "or video codecs in audio capabilities.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    // If robustness is not the empty string and contains an unrecognized
+    // value or a value not supported by implementation, continue to the
+    // next iteration. String comparison is case-sensitive.
+    if (!robustness.IsEmpty()) {
+      if (majorType == Audio && !aKeySystem.mAudioRobustness.Contains(robustness)) {
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "unsupported robustness string.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get());
+        continue;
+      }
+      if (majorType == Video && !aKeySystem.mVideoRobustness.Contains(robustness)) {
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "unsupported robustness string.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get());
+        continue;
+      }
+      // Note: specified robustness requirements are satisfied.
+    }
+
+    // If the user agent and implementation definitely support playback of
+    // encrypted media data for the combination of container, media types,
+    // robustness and local accumulated configuration in combination with
+    // restrictions...
+    const auto& containerSupport = isMP4 ? aKeySystem.mMP4 : aKeySystem.mWebM;
+    if (!CanDecryptAndDecode(aKeySystem.mKeySystem,
+                             contentType,
+                             majorType,
+                             containerSupport,
+                             codecs,
+                             aDiagnostics)) {
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "codec unsupported by CDM requested.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get());
+        continue;
+    }
+
+    // ... add requested media capability to supported media capabilities.
+    if (!supportedCapabilities.AppendElement(capabilities, mozilla::fallible)) {
+      NS_WARNING("GetSupportedCapabilities: Malloc failure");
+      return Sequence<MediaKeySystemMediaCapability>();
+    }
+
+    // Note: omitting steps 3.13.2, our robustness is not sophisticated enough
+    // to require considering all requirements together.
+  }
+  return Move(supportedCapabilities);
+}
+
+// "Get Supported Configuration and Consent" algorithm, steps 4-7 for
+// distinctive identifier, and steps 8-11 for persistent state. The steps
+// are the same for both requirements/features, so we factor them out into
+// a single function.
+static bool
+CheckRequirement(const MediaKeysRequirement aRequirement,
+                 const KeySystemFeatureSupport aFeatureSupport,
+                 MediaKeysRequirement& aOutRequirement)
+{
+  // Let requirement be the value of candidate configuration's member.
+  MediaKeysRequirement requirement = aRequirement;
+  // If requirement is "optional" and feature is not allowed according to
+  // restrictions, set requirement to "not-allowed".
+  if (aRequirement == MediaKeysRequirement::Optional &&
+      aFeatureSupport == KeySystemFeatureSupport::Prohibited) {
+    requirement = MediaKeysRequirement::Not_allowed;
+  }
+
+  // Follow the steps for requirement from the following list:
+  switch (requirement) {
+    case MediaKeysRequirement::Required: {
+      // If the implementation does not support use of requirement in combination
+      // with accumulated configuration and restrictions, return NotSupported.
+      if (aFeatureSupport == KeySystemFeatureSupport::Prohibited) {
+        return false;
+      }
+      break;
+    }
+    case MediaKeysRequirement::Optional: {
+      // Continue with the following steps.
+      break;
+    }
+    case MediaKeysRequirement::Not_allowed: {
+      // If the implementation requires use of feature in combination with
+      // accumulated configuration and restrictions, return NotSupported.
+      if (aFeatureSupport == KeySystemFeatureSupport::Required) {
+        return false;
+      }
+      break;
+    }
+    default: {
+      return false;
+    }
+  }
+
+  // Set the requirement member of accumulated configuration to equal
+  // calculated requirement.
+  aOutRequirement = requirement;
+
+  return true;
+}
+
+// 3.1.2.2, step 12
+// Follow the steps for the first matching condition from the following list:
+// If the sessionTypes member is present in candidate configuration.
+// Let session types be candidate configuration's sessionTypes member.
+// Otherwise let session types be ["temporary"].
+// Note: This returns an empty array on malloc failure.
+static Sequence<nsString>
+UnboxSessionTypes(const Optional<Sequence<nsString>>& aSessionTypes)
+{
+  Sequence<nsString> sessionTypes;
+  if (aSessionTypes.WasPassed()) {
+    sessionTypes = aSessionTypes.Value();
+  } else {
+    using MediaKeySessionTypeValues::strings;
+    const char* temporary = strings[static_cast<uint32_t>(MediaKeySessionType::Temporary)].value;
+    // Note: fallible. Results in an empty array.
+    sessionTypes.AppendElement(NS_ConvertUTF8toUTF16(nsDependentCString(temporary)), mozilla::fallible);
+  }
+  return sessionTypes;
+}
+
+// 3.1.2.2 Get Supported Configuration and Consent
+static bool
+GetSupportedConfig(const KeySystemConfig& aKeySystem,
+                   const MediaKeySystemConfiguration& aCandidate,
+                   MediaKeySystemConfiguration& aOutConfig,
+                   DecoderDoctorDiagnostics* aDiagnostics)
+{
+  // Let accumulated configuration be a new MediaKeySystemConfiguration dictionary.
+  MediaKeySystemConfiguration config;
+  // Set the label member of accumulated configuration to equal the label member of
+  // candidate configuration.
+  config.mLabel = aCandidate.mLabel;
+  // If the initDataTypes member of candidate configuration is non-empty, run the
+  // following steps:
+  if (!aCandidate.mInitDataTypes.IsEmpty()) {
+    // Let supported types be an empty sequence of DOMStrings.
+    nsTArray<nsString> supportedTypes;
+    // For each value in candidate configuration's initDataTypes member:
+    for (const nsString& initDataType : aCandidate.mInitDataTypes) {
+      // Let initDataType be the value.
+      // If the implementation supports generating requests based on initDataType,
+      // add initDataType to supported types. String comparison is case-sensitive.
+      // The empty string is never supported.
+      if (aKeySystem.mInitDataTypes.Contains(initDataType)) {
+        supportedTypes.AppendElement(initDataType);
+      }
+    }
+    // If supported types is empty, return NotSupported.
+    if (supportedTypes.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "no supported initDataTypes provided.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // Set the initDataTypes member of accumulated configuration to supported types.
+    if (!config.mInitDataTypes.Assign(supportedTypes)) {
+      return false;
+    }
+  }
+
+  if (!CheckRequirement(aCandidate.mDistinctiveIdentifier,
+                        aKeySystem.mDistinctiveIdentifier,
+                        config.mDistinctiveIdentifier)) {
+    EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+            "distinctiveIdentifier requirement not satisfied.",
+            NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+    return false;
+  }
+
+  if (!CheckRequirement(aCandidate.mPersistentState,
+                        aKeySystem.mPersistentState,
+                        config.mPersistentState)) {
+    EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+            "persistentState requirement not satisfied.",
+            NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+    return false;
+  }
+
+  Sequence<nsString> sessionTypes(UnboxSessionTypes(aCandidate.mSessionTypes));
+  if (sessionTypes.IsEmpty()) {
+    // Malloc failure.
+    return false;
+  }
+
+  // For each value in session types:
+  for (const auto& sessionTypeString : sessionTypes) {
+    // Let session type be the value.
+    MediaKeySessionType sessionType;
+    if (!ToSessionType(sessionTypeString, sessionType)) {
+      // (Assume invalid sessionType is unsupported as per steps below).
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "invalid session type specified.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // If accumulated configuration's persistentState value is "not-allowed"
+    // and the Is persistent session type? algorithm returns true for session
+    // type return NotSupported.
+    if (config.mPersistentState == MediaKeysRequirement::Not_allowed &&
+        IsPersistentSessionType(sessionType)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "persistent session requested but keysystem doesn't"
+              "support persistent state.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // If the implementation does not support session type in combination
+    // with accumulated configuration and restrictions for other reasons,
+    // return NotSupported.
+    if (!aKeySystem.mSessionTypes.Contains(sessionType)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "session type '%s' unsupported by keySystem.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get(),
+              NS_ConvertUTF16toUTF8(sessionTypeString).get());
+      return false;
+    }
+    // If accumulated configuration's persistentState value is "optional"
+    // and the result of running the Is persistent session type? algorithm
+    // on session type is true, change accumulated configuration's
+    // persistentState value to "required".
+    if (config.mPersistentState == MediaKeysRequirement::Optional &&
+        IsPersistentSessionType(sessionType)) {
+      config.mPersistentState = MediaKeysRequirement::Required;
+    }
+  }
+  // Set the sessionTypes member of accumulated configuration to session types.
+  config.mSessionTypes.Construct(Move(sessionTypes));
+
+  // If the videoCapabilities and audioCapabilities members in candidate
+  // configuration are both empty, return NotSupported.
+  // TODO: Most sites using EME still don't pass capabilities, so we
+  // can't reject on it yet without breaking them. So add this later.
+
+  // If the videoCapabilities member in candidate configuration is non-empty:
+  if (!aCandidate.mVideoCapabilities.IsEmpty()) {
+    // Let video capabilities be the result of executing the Get Supported
+    // Capabilities for Audio/Video Type algorithm on Video, candidate
+    // configuration's videoCapabilities member, accumulated configuration,
+    // and restrictions.
+    Sequence<MediaKeySystemMediaCapability> caps =
+      GetSupportedCapabilities(Video,
+                               aCandidate.mVideoCapabilities,
+                               config,
+                               aKeySystem,
+                               aDiagnostics);
+    // If video capabilities is null, return NotSupported.
+    if (caps.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "no supported video capabilities.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // Set the videoCapabilities member of accumulated configuration to video capabilities.
+    config.mVideoCapabilities = Move(caps);
+  } else {
+    // Otherwise:
+    // Set the videoCapabilities member of accumulated configuration to an empty sequence.
+  }
+
+  // If the audioCapabilities member in candidate configuration is non-empty:
+  if (!aCandidate.mAudioCapabilities.IsEmpty()) {
+    // Let audio capabilities be the result of executing the Get Supported Capabilities
+    // for Audio/Video Type algorithm on Audio, candidate configuration's audioCapabilities
+    // member, accumulated configuration, and restrictions.
+    Sequence<MediaKeySystemMediaCapability> caps =
+      GetSupportedCapabilities(Audio,
+                               aCandidate.mAudioCapabilities,
+                               config,
+                               aKeySystem,
+                               aDiagnostics);
+    // If audio capabilities is null, return NotSupported.
+    if (caps.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "no supported audio capabilities.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // Set the audioCapabilities member of accumulated configuration to audio capabilities.
+    config.mAudioCapabilities = Move(caps);
+  } else {
+    // Otherwise:
+    // Set the audioCapabilities member of accumulated configuration to an empty sequence.
+  }
+
+  // If accumulated configuration's distinctiveIdentifier value is "optional", follow the
+  // steps for the first matching condition from the following list:
+  if (config.mDistinctiveIdentifier == MediaKeysRequirement::Optional) {
+    // If the implementation requires use Distinctive Identifier(s) or
+    // Distinctive Permanent Identifier(s) for any of the combinations
+    // in accumulated configuration
+    if (aKeySystem.mDistinctiveIdentifier == KeySystemFeatureSupport::Required) {
+      // Change accumulated configuration's distinctiveIdentifier value to "required".
+      config.mDistinctiveIdentifier = MediaKeysRequirement::Required;
+    } else {
+      // Otherwise, change accumulated configuration's distinctiveIdentifier
+      // value to "not-allowed".
+      config.mDistinctiveIdentifier = MediaKeysRequirement::Not_allowed;
+    }
+  }
+
+  // If accumulated configuration's persistentState value is "optional", follow the
+  // steps for the first matching condition from the following list:
+  if (config.mPersistentState == MediaKeysRequirement::Optional) {
+    // If the implementation requires persisting state for any of the combinations
+    // in accumulated configuration
+    if (aKeySystem.mPersistentState == KeySystemFeatureSupport::Required) {
+      // Change accumulated configuration's persistentState value to "required".
+      config.mPersistentState = MediaKeysRequirement::Required;
+    } else {
+      // Otherwise, change accumulated configuration's persistentState
+      // value to "not-allowed".
+      config.mPersistentState = MediaKeysRequirement::Not_allowed;
+    }
+  }
+
+  // Note: Omitting steps 20-22. We don't ask for consent.
+
+#if defined(XP_WIN)
+  // Widevine CDM doesn't include an AAC decoder. So if WMF can't decode AAC,
+  // and a codec wasn't specified, be conservative and reject the MediaKeys request.
+  if (IsWidevineKeySystem(aKeySystem.mKeySystem) &&
+      (aCandidate.mAudioCapabilities.IsEmpty() ||
+       aCandidate.mVideoCapabilities.IsEmpty()) &&
+     !WMFDecoderModule::HasAAC()) {
+    if (aDiagnostics) {
+      aDiagnostics->SetKeySystemIssue(
+        DecoderDoctorDiagnostics::eWidevineWithNoWMF);
+    }
+    EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+            "WMF required for Widevine decoding, but it's not available.",
+            NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+    return false;
+  }
+#endif
+
+  // Return accumulated configuration.
+  aOutConfig = config;
+
+  return true;
+}
+
+/* static */
+bool
+MediaKeySystemAccess::GetSupportedConfig(const nsAString& aKeySystem,
+                                         const Sequence<MediaKeySystemConfiguration>& aConfigs,
+                                         MediaKeySystemConfiguration& aOutConfig,
+                                         DecoderDoctorDiagnostics* aDiagnostics)
+{
+  KeySystemConfig implementation;
+  if (!GetKeySystemConfig(aKeySystem, implementation)) {
+    return false;
+  }
+  for (const MediaKeySystemConfiguration& candidate : aConfigs) {
+    if (mozilla::dom::GetSupportedConfig(implementation,
+                                         candidate,
+                                         aOutConfig,
+                                         aDiagnostics)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+
+/* static */
+void
+MediaKeySystemAccess::NotifyObservers(nsPIDOMWindowInner* aWindow,
+                                      const nsAString& aKeySystem,
+                                      MediaKeySystemStatus aStatus)
+{
+  RequestMediaKeySystemAccessNotification data;
+  data.mKeySystem = aKeySystem;
+  data.mStatus = aStatus;
+  nsAutoString json;
+  data.ToJSON(json);
+  EME_LOG("MediaKeySystemAccess::NotifyObservers() %s", NS_ConvertUTF16toUTF8(json).get());
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (obs) {
+    obs->NotifyObservers(aWindow, "mediakeys-request", json.get());
+  }
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeySystemAccess.h b/dom/media/eme/MediaKeySystemAccess.h
new file mode 100644
index 0000000000..a166ac22ea
--- /dev/null
+++ b/dom/media/eme/MediaKeySystemAccess.h
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeySystemAccess_h
+#define mozilla_dom_MediaKeySystemAccess_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/MediaKeySystemAccessBinding.h"
+#include "mozilla/dom/MediaKeysRequestStatusBinding.h"
+
+#include "js/TypeDecls.h"
+
+namespace mozilla {
+
+class DecoderDoctorDiagnostics;
+
+namespace dom {
+
+class MediaKeySystemAccess final : public nsISupports,
+                                   public nsWrapperCache
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaKeySystemAccess)
+
+public:
+  explicit MediaKeySystemAccess(nsPIDOMWindowInner* aParent,
+                                const nsAString& aKeySystem,
+                                const MediaKeySystemConfiguration& aConfig);
+
+protected:
+  ~MediaKeySystemAccess();
+
+public:
+  nsPIDOMWindowInner* GetParentObject() const;
+
+  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  void GetKeySystem(nsString& aRetVal) const;
+
+  void GetConfiguration(MediaKeySystemConfiguration& aConfig);
+
+  already_AddRefed<Promise> CreateMediaKeys(ErrorResult& aRv);
+
+  static MediaKeySystemStatus GetKeySystemStatus(const nsAString& aKeySystem,
+                                                 nsACString& aOutExceptionMessage);
+
+  static bool IsSupported(const nsAString& aKeySystem,
+                          const Sequence<MediaKeySystemConfiguration>& aConfigs,
+                          DecoderDoctorDiagnostics* aDiagnostics);
+
+  static void NotifyObservers(nsPIDOMWindowInner* aWindow,
+                              const nsAString& aKeySystem,
+                              MediaKeySystemStatus aStatus);
+
+  static bool GetSupportedConfig(const nsAString& aKeySystem,
+                                 const Sequence<MediaKeySystemConfiguration>& aConfigs,
+                                 MediaKeySystemConfiguration& aOutConfig,
+                                 DecoderDoctorDiagnostics* aDiagnostics);
+
+  static bool KeySystemSupportsInitDataType(const nsAString& aKeySystem,
+                                            const nsAString& aInitDataType);
+
+private:
+  nsCOMPtr<nsPIDOMWindowInner> mParent;
+  const nsString mKeySystem;
+  const MediaKeySystemConfiguration mConfig;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_MediaKeySystemAccess_h
diff --git a/dom/media/eme/MediaKeySystemAccessManager.cpp b/dom/media/eme/MediaKeySystemAccessManager.cpp
new file mode 100644
index 0000000000..8fefc62ec7
--- /dev/null
+++ b/dom/media/eme/MediaKeySystemAccessManager.cpp
@@ -0,0 +1,340 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaKeySystemAccessManager.h"
+#include "DecoderDoctorDiagnostics.h"
+#include "MediaPrefs.h"
+#include "mozilla/EMEUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIObserverService.h"
+#include "mozilla/Services.h"
+#include "mozilla/DetailedPromise.h"
+#ifdef XP_WIN
+#include "mozilla/WindowsVersion.h"
+#endif
+#ifdef XP_MACOSX
+#include "nsCocoaFeatures.h"
+#endif
+#include "nsPrintfCString.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeySystemAccessManager)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsIObserver)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeySystemAccessManager)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeySystemAccessManager)
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(MediaKeySystemAccessManager)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaKeySystemAccessManager)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mWindow)
+  for (size_t i = 0; i < tmp->mRequests.Length(); i++) {
+    tmp->mRequests[i].RejectPromise(NS_LITERAL_CSTRING("Promise still outstanding at MediaKeySystemAccessManager GC"));
+    tmp->mRequests[i].CancelTimer();
+    NS_IMPL_CYCLE_COLLECTION_UNLINK(mRequests[i].mPromise)
+  }
+  tmp->mRequests.Clear();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(MediaKeySystemAccessManager)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWindow)
+  for (size_t i = 0; i < tmp->mRequests.Length(); i++) {
+    NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRequests[i].mPromise)
+  }
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+MediaKeySystemAccessManager::MediaKeySystemAccessManager(nsPIDOMWindowInner* aWindow)
+  : mWindow(aWindow)
+  , mAddedObservers(false)
+{
+}
+
+MediaKeySystemAccessManager::~MediaKeySystemAccessManager()
+{
+  Shutdown();
+}
+
+void
+MediaKeySystemAccessManager::Request(DetailedPromise* aPromise,
+                                     const nsAString& aKeySystem,
+                                     const Sequence<MediaKeySystemConfiguration>& aConfigs)
+{
+  Request(aPromise, aKeySystem, aConfigs, RequestType::Initial);
+}
+
+void
+MediaKeySystemAccessManager::Request(DetailedPromise* aPromise,
+                                     const nsAString& aKeySystem,
+                                     const Sequence<MediaKeySystemConfiguration>& aConfigs,
+                                     RequestType aType)
+{
+  EME_LOG("MediaKeySystemAccessManager::Request %s", NS_ConvertUTF16toUTF8(aKeySystem).get());
+
+  if (aKeySystem.IsEmpty()) {
+    aPromise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+                          NS_LITERAL_CSTRING("Key system string is empty"));
+    // Don't notify DecoderDoctor, as there's nothing we or the user can
+    // do to fix this situation; the site is using the API wrong.
+    return;
+  }
+  if (aConfigs.IsEmpty()) {
+    aPromise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+                          NS_LITERAL_CSTRING("Candidate MediaKeySystemConfigs is empty"));
+    // Don't notify DecoderDoctor, as there's nothing we or the user can
+    // do to fix this situation; the site is using the API wrong.
+    return;
+  }
+
+  DecoderDoctorDiagnostics diagnostics;
+
+  // Ensure keysystem is supported.
+  if (!IsWidevineKeySystem(aKeySystem) &&
+      !IsClearkeyKeySystem(aKeySystem) &&
+      !IsPrimetimeKeySystem(aKeySystem)) {
+    // Not to inform user, because nothing to do if the keySystem is not
+    // supported.
+    aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
+                          NS_LITERAL_CSTRING("Key system is unsupported"));
+    diagnostics.StoreMediaKeySystemAccess(mWindow->GetExtantDoc(),
+                                          aKeySystem, false, __func__);
+    return;
+  }
+
+  if (!MediaPrefs::EMEEnabled() && !IsClearkeyKeySystem(aKeySystem)) {
+    // EME disabled by user, send notification to chrome so UI can inform user.
+    // Clearkey is allowed even when EME is disabled because we want the pref
+    // "media.eme.enabled" only taking effect on proprietary DRMs.
+    MediaKeySystemAccess::NotifyObservers(mWindow,
+                                          aKeySystem,
+                                          MediaKeySystemStatus::Api_disabled);
+    aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
+                          NS_LITERAL_CSTRING("EME has been preffed off"));
+    diagnostics.StoreMediaKeySystemAccess(mWindow->GetExtantDoc(),
+                                          aKeySystem, false, __func__);
+    return;
+  }
+
+  nsAutoCString message;
+  MediaKeySystemStatus status =
+    MediaKeySystemAccess::GetKeySystemStatus(aKeySystem, message);
+
+  nsPrintfCString msg("MediaKeySystemAccess::GetKeySystemStatus(%s) "
+                      "result=%s msg='%s'",
+                      NS_ConvertUTF16toUTF8(aKeySystem).get(),
+                      MediaKeySystemStatusValues::strings[(size_t)status].value,
+                      message.get());
+  LogToBrowserConsole(NS_ConvertUTF8toUTF16(msg));
+
+  if (status == MediaKeySystemStatus::Cdm_not_installed &&
+      (IsPrimetimeKeySystem(aKeySystem) || IsWidevineKeySystem(aKeySystem))) {
+    // These are cases which could be resolved by downloading a new(er) CDM.
+    // When we send the status to chrome, chrome's GMPProvider will attempt to
+    // download or update the CDM. In AwaitInstall() we add listeners to wait
+    // for the update to complete, and we'll call this function again with
+    // aType==Subsequent once the download has completed and the GMPService
+    // has had a new plugin added. AwaitInstall() sets a timer to fail if the
+    // update/download takes too long or fails.
+    if (aType == RequestType::Initial &&
+        AwaitInstall(aPromise, aKeySystem, aConfigs)) {
+      // Notify chrome that we're going to wait for the CDM to download/update.
+      // Note: If we're re-trying, we don't re-send the notification,
+      // as chrome is already displaying the "we can't play, updating"
+      // notification.
+      MediaKeySystemAccess::NotifyObservers(mWindow, aKeySystem, status);
+    } else {
+      // We waited or can't wait for an update and we still can't service
+      // the request. Give up. Chrome will still be showing a "I can't play,
+      // updating" notification.
+      aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
+                            NS_LITERAL_CSTRING("Gave up while waiting for a CDM update"));
+    }
+    diagnostics.StoreMediaKeySystemAccess(mWindow->GetExtantDoc(),
+                                          aKeySystem, false, __func__);
+    return;
+  }
+  if (status != MediaKeySystemStatus::Available) {
+    // Failed due to user disabling something, send a notification to
+    // chrome, so we can show some UI to explain how the user can rectify
+    // the situation.
+    MediaKeySystemAccess::NotifyObservers(mWindow, aKeySystem, status);
+    aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR, message);
+    return;
+  }
+
+  MediaKeySystemConfiguration config;
+  if (MediaKeySystemAccess::GetSupportedConfig(aKeySystem, aConfigs, config, &diagnostics)) {
+    RefPtr<MediaKeySystemAccess> access(
+      new MediaKeySystemAccess(mWindow, aKeySystem, config));
+    aPromise->MaybeResolve(access);
+    diagnostics.StoreMediaKeySystemAccess(mWindow->GetExtantDoc(),
+                                          aKeySystem, true, __func__);
+    return;
+  }
+  // Not to inform user, because nothing to do if the corresponding keySystem
+  // configuration is not supported.
+  aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
+                        NS_LITERAL_CSTRING("Key system configuration is not supported"));
+  diagnostics.StoreMediaKeySystemAccess(mWindow->GetExtantDoc(),
+                                        aKeySystem, false, __func__);
+}
+
+MediaKeySystemAccessManager::PendingRequest::PendingRequest(DetailedPromise* aPromise,
+                                                            const nsAString& aKeySystem,
+                                                            const Sequence<MediaKeySystemConfiguration>& aConfigs,
+                                                            nsITimer* aTimer)
+  : mPromise(aPromise)
+  , mKeySystem(aKeySystem)
+  , mConfigs(aConfigs)
+  , mTimer(aTimer)
+{
+  MOZ_COUNT_CTOR(MediaKeySystemAccessManager::PendingRequest);
+}
+
+MediaKeySystemAccessManager::PendingRequest::PendingRequest(const PendingRequest& aOther)
+  : mPromise(aOther.mPromise)
+  , mKeySystem(aOther.mKeySystem)
+  , mConfigs(aOther.mConfigs)
+  , mTimer(aOther.mTimer)
+{
+  MOZ_COUNT_CTOR(MediaKeySystemAccessManager::PendingRequest);
+}
+
+MediaKeySystemAccessManager::PendingRequest::~PendingRequest()
+{
+  MOZ_COUNT_DTOR(MediaKeySystemAccessManager::PendingRequest);
+}
+
+void
+MediaKeySystemAccessManager::PendingRequest::CancelTimer()
+{
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+}
+
+void
+MediaKeySystemAccessManager::PendingRequest::RejectPromise(const nsCString& aReason)
+{
+  if (mPromise) {
+    mPromise->MaybeReject(NS_ERROR_DOM_INVALID_ACCESS_ERR, aReason);
+  }
+}
+
+bool
+MediaKeySystemAccessManager::AwaitInstall(DetailedPromise* aPromise,
+                                          const nsAString& aKeySystem,
+                                          const Sequence<MediaKeySystemConfiguration>& aConfigs)
+{
+  EME_LOG("MediaKeySystemAccessManager::AwaitInstall %s", NS_ConvertUTF16toUTF8(aKeySystem).get());
+
+  if (!EnsureObserversAdded()) {
+    NS_WARNING("Failed to add pref observer");
+    return false;
+  }
+
+  nsCOMPtr<nsITimer> timer(do_CreateInstance("@mozilla.org/timer;1"));
+  if (!timer || NS_FAILED(timer->Init(this, 60 * 1000, nsITimer::TYPE_ONE_SHOT))) {
+    NS_WARNING("Failed to create timer to await CDM install.");
+    return false;
+  }
+
+  mRequests.AppendElement(PendingRequest(aPromise, aKeySystem, aConfigs, timer));
+  return true;
+}
+
+void
+MediaKeySystemAccessManager::RetryRequest(PendingRequest& aRequest)
+{
+  aRequest.CancelTimer();
+  Request(aRequest.mPromise, aRequest.mKeySystem, aRequest.mConfigs, RequestType::Subsequent);
+}
+
+nsresult
+MediaKeySystemAccessManager::Observe(nsISupports* aSubject,
+                                     const char* aTopic,
+                                     const char16_t* aData)
+{
+  EME_LOG("MediaKeySystemAccessManager::Observe %s", aTopic);
+
+  if (!strcmp(aTopic, "gmp-changed")) {
+    // Filter out the requests where the CDM's install-status is no longer
+    // "unavailable". This will be the CDMs which have downloaded since the
+    // initial request.
+    // Note: We don't have a way to communicate from chrome that the CDM has
+    // failed to download, so we'll just let the timeout fail us in that case.
+    nsTArray<PendingRequest> requests;
+    for (size_t i = mRequests.Length(); i-- > 0; ) {
+      PendingRequest& request = mRequests[i];
+      nsAutoCString message;
+      MediaKeySystemStatus status =
+        MediaKeySystemAccess::GetKeySystemStatus(request.mKeySystem, message);
+      if (status == MediaKeySystemStatus::Cdm_not_installed) {
+        // Not yet installed, don't retry. Keep waiting until timeout.
+        continue;
+      }
+      // Status has changed, retry request.
+      requests.AppendElement(Move(request));
+      mRequests.RemoveElementAt(i);
+    }
+    // Retry all pending requests, but this time fail if the CDM is not installed.
+    for (PendingRequest& request : requests) {
+      RetryRequest(request);
+    }
+  } else if (!strcmp(aTopic, "timer-callback")) {
+    // Find the timer that expired and re-run the request for it.
+    nsCOMPtr<nsITimer> timer(do_QueryInterface(aSubject));
+    for (size_t i = 0; i < mRequests.Length(); i++) {
+      if (mRequests[i].mTimer == timer) {
+        EME_LOG("MediaKeySystemAccessManager::AwaitInstall resuming request");
+        PendingRequest request = mRequests[i];
+        mRequests.RemoveElementAt(i);
+        RetryRequest(request);
+        break;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+bool
+MediaKeySystemAccessManager::EnsureObserversAdded()
+{
+  if (mAddedObservers) {
+    return true;
+  }
+
+  nsCOMPtr<nsIObserverService> obsService = mozilla::services::GetObserverService();
+  if (NS_WARN_IF(!obsService)) {
+    return false;
+  }
+  mAddedObservers = NS_SUCCEEDED(obsService->AddObserver(this, "gmp-changed", false));
+  return mAddedObservers;
+}
+
+void
+MediaKeySystemAccessManager::Shutdown()
+{
+  EME_LOG("MediaKeySystemAccessManager::Shutdown");
+  nsTArray<PendingRequest> requests(Move(mRequests));
+  for (PendingRequest& request : requests) {
+    // Cancel all requests; we're shutting down.
+    request.CancelTimer();
+    request.RejectPromise(NS_LITERAL_CSTRING("Promise still outstanding at MediaKeySystemAccessManager shutdown"));
+  }
+  if (mAddedObservers) {
+    nsCOMPtr<nsIObserverService> obsService = mozilla::services::GetObserverService();
+    if (obsService) {
+      obsService->RemoveObserver(this, "gmp-changed");
+      mAddedObservers = false;
+    }
+  }
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeySystemAccessManager.h b/dom/media/eme/MediaKeySystemAccessManager.h
new file mode 100644
index 0000000000..9c092248e2
--- /dev/null
+++ b/dom/media/eme/MediaKeySystemAccessManager.h
@@ -0,0 +1,83 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MediaKeySystemAccessManager_h
+#define mozilla_dom_MediaKeySystemAccessManager_h
+
+#include "mozilla/dom/MediaKeySystemAccess.h"
+#include "nsIObserver.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsISupportsImpl.h"
+#include "nsITimer.h"
+
+namespace mozilla {
+namespace dom {
+
+class DetailedPromise;
+class TestGMPVideoDecoder;
+
+class MediaKeySystemAccessManager final : public nsIObserver
+{
+public:
+
+  explicit MediaKeySystemAccessManager(nsPIDOMWindowInner* aWindow);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(MediaKeySystemAccessManager, nsIObserver)
+  NS_DECL_NSIOBSERVER
+
+  void Request(DetailedPromise* aPromise,
+               const nsAString& aKeySystem,
+               const Sequence<MediaKeySystemConfiguration>& aConfig);
+
+  void Shutdown();
+
+  struct PendingRequest {
+    PendingRequest(DetailedPromise* aPromise,
+                   const nsAString& aKeySystem,
+                   const Sequence<MediaKeySystemConfiguration>& aConfig,
+                   nsITimer* aTimer);
+    PendingRequest(const PendingRequest& aOther);
+    ~PendingRequest();
+    void CancelTimer();
+    void RejectPromise(const nsCString& aReason);
+
+    RefPtr<DetailedPromise> mPromise;
+    const nsString mKeySystem;
+    const Sequence<MediaKeySystemConfiguration> mConfigs;
+    nsCOMPtr<nsITimer> mTimer;
+  };
+
+private:
+
+  enum RequestType {
+    Initial,
+    Subsequent
+  };
+
+  void Request(DetailedPromise* aPromise,
+               const nsAString& aKeySystem,
+               const Sequence<MediaKeySystemConfiguration>& aConfig,
+               RequestType aType);
+
+  ~MediaKeySystemAccessManager();
+
+  bool EnsureObserversAdded();
+
+  bool AwaitInstall(DetailedPromise* aPromise,
+                    const nsAString& aKeySystem,
+                    const Sequence<MediaKeySystemConfiguration>& aConfig);
+
+  void RetryRequest(PendingRequest& aRequest);
+
+  nsTArray<PendingRequest> mRequests;
+
+  nsCOMPtr<nsPIDOMWindowInner> mWindow;
+  bool mAddedObservers;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif
diff --git a/dom/media/eme/MediaKeys.cpp b/dom/media/eme/MediaKeys.cpp
new file mode 100644
index 0000000000..eedd675e4f
--- /dev/null
+++ b/dom/media/eme/MediaKeys.cpp
@@ -0,0 +1,593 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/MediaKeys.h"
+#include "GMPService.h"
+#include "mozilla/dom/HTMLMediaElement.h"
+#include "mozilla/dom/MediaKeysBinding.h"
+#include "mozilla/dom/MediaKeyMessageEvent.h"
+#include "mozilla/dom/MediaKeyError.h"
+#include "mozilla/dom/MediaKeySession.h"
+#include "mozilla/dom/DOMException.h"
+#include "mozilla/dom/UnionTypes.h"
+#include "mozilla/Telemetry.h"
+#include "GMPCDMProxy.h"
+#ifdef MOZ_WIDGET_ANDROID
+#include "mozilla/MediaDrmCDMProxy.h"
+#endif
+#include "mozilla/EMEUtils.h"
+#include "nsContentUtils.h"
+#include "nsIScriptObjectPrincipal.h"
+#include "nsContentTypeParser.h"
+#ifdef MOZ_FMP4
+#include "MP4Decoder.h"
+#endif
+#ifdef XP_WIN
+#include "mozilla/WindowsVersion.h"
+#endif
+#include "nsContentCID.h"
+#include "nsServiceManagerUtils.h"
+#include "mozilla/dom/MediaKeySystemAccess.h"
+#include "nsPrintfCString.h"
+
+namespace mozilla {
+
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeys,
+                                      mElement,
+                                      mParent,
+                                      mKeySessions,
+                                      mPromises,
+                                      mPendingSessions);
+NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeys)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeys)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeys)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+MediaKeys::MediaKeys(nsPIDOMWindowInner* aParent,
+                     const nsAString& aKeySystem,
+                     const MediaKeySystemConfiguration& aConfig)
+  : mParent(aParent)
+  , mKeySystem(aKeySystem)
+  , mCreatePromiseId(0)
+  , mConfig(aConfig)
+{
+  EME_LOG("MediaKeys[%p] constructed keySystem=%s",
+          this, NS_ConvertUTF16toUTF8(mKeySystem).get());
+}
+
+MediaKeys::~MediaKeys()
+{
+  Shutdown();
+  EME_LOG("MediaKeys[%p] destroyed", this);
+}
+
+void
+MediaKeys::Terminated()
+{
+  EME_LOG("MediaKeys[%p] CDM crashed unexpectedly", this);
+
+  KeySessionHashMap keySessions;
+  // Remove entries during iteration will screw it. Make a copy first.
+  for (auto iter = mKeySessions.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<MediaKeySession>& session = iter.Data();
+    keySessions.Put(session->GetSessionId(), session);
+  }
+  for (auto iter = keySessions.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<MediaKeySession>& session = iter.Data();
+    session->OnClosed();
+  }
+  keySessions.Clear();
+  MOZ_ASSERT(mKeySessions.Count() == 0);
+
+  // Notify the element about that CDM has terminated.
+  if (mElement) {
+    mElement->DecodeError(NS_ERROR_DOM_MEDIA_CDM_ERR);
+  }
+
+  Shutdown();
+}
+
+void
+MediaKeys::Shutdown()
+{
+  if (mProxy) {
+    mProxy->Shutdown();
+    mProxy = nullptr;
+  }
+
+  RefPtr<MediaKeys> kungFuDeathGrip = this;
+
+  for (auto iter = mPromises.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<dom::DetailedPromise>& promise = iter.Data();
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Promise still outstanding at MediaKeys shutdown"));
+    Release();
+  }
+  mPromises.Clear();
+}
+
+nsPIDOMWindowInner*
+MediaKeys::GetParentObject() const
+{
+  return mParent;
+}
+
+JSObject*
+MediaKeys::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeysBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+MediaKeys::GetKeySystem(nsString& aOutKeySystem) const
+{
+  aOutKeySystem.Assign(mKeySystem);
+}
+
+already_AddRefed<DetailedPromise>
+MediaKeys::SetServerCertificate(const ArrayBufferViewOrArrayBuffer& aCert, ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeys.setServerCertificate")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  if (!mProxy) {
+    NS_WARNING("Tried to use a MediaKeys without a CDM");
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Null CDM in MediaKeys.setServerCertificate()"));
+    return promise.forget();
+  }
+
+  nsTArray<uint8_t> data;
+  CopyArrayBufferViewOrArrayBufferData(aCert, data);
+  if (data.IsEmpty()) {
+    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
+      NS_LITERAL_CSTRING("Empty certificate passed to MediaKeys.setServerCertificate()"));
+    return promise.forget();
+  }
+
+  mProxy->SetServerCertificate(StorePromise(promise), data);
+  return promise.forget();
+}
+
+already_AddRefed<DetailedPromise>
+MediaKeys::MakePromise(ErrorResult& aRv, const nsACString& aName)
+{
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
+  if (!global) {
+    NS_WARNING("Passed non-global to MediaKeys ctor!");
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return nullptr;
+  }
+  return DetailedPromise::Create(global, aRv, aName);
+}
+
+PromiseId
+MediaKeys::StorePromise(DetailedPromise* aPromise)
+{
+  static uint32_t sEMEPromiseCount = 1;
+  MOZ_ASSERT(aPromise);
+  uint32_t id = sEMEPromiseCount++;
+
+  EME_LOG("MediaKeys[%p]::StorePromise() id=%d", this, id);
+
+  // Keep MediaKeys alive for the lifetime of its promises. Any still-pending
+  // promises are rejected in Shutdown().
+  AddRef();
+
+#ifdef DEBUG
+  // We should not have already stored this promise!
+  for (auto iter = mPromises.ConstIter(); !iter.Done(); iter.Next()) {
+    MOZ_ASSERT(iter.Data() != aPromise);
+  }
+#endif
+
+  mPromises.Put(id, aPromise);
+  return id;
+}
+
+void
+MediaKeys::ConnectPendingPromiseIdWithToken(PromiseId aId, uint32_t aToken)
+{
+  // Should only be called from MediaKeySession::GenerateRequest.
+  mPromiseIdToken.Put(aId, aToken);
+  EME_LOG("MediaKeys[%p]::ConnectPendingPromiseIdWithToken() id=%u => token(%u)",
+          this, aId, aToken);
+}
+
+already_AddRefed<DetailedPromise>
+MediaKeys::RetrievePromise(PromiseId aId)
+{
+  if (!mPromises.Contains(aId)) {
+    NS_WARNING(nsPrintfCString("Tried to retrieve a non-existent promise id=%d", aId).get());
+    return nullptr;
+  }
+  RefPtr<DetailedPromise> promise;
+  mPromises.Remove(aId, getter_AddRefs(promise));
+  Release();
+  return promise.forget();
+}
+
+void
+MediaKeys::RejectPromise(PromiseId aId, nsresult aExceptionCode,
+                         const nsCString& aReason)
+{
+  EME_LOG("MediaKeys[%p]::RejectPromise(%d, 0x%x)", this, aId, aExceptionCode);
+
+  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
+  if (!promise) {
+    return;
+  }
+
+  // This promise could be a createSession or loadSession promise,
+  // so we might have a pending session waiting to be resolved into
+  // the promise on success. We've been directed to reject to promise,
+  // so we can throw away the corresponding session object.
+  uint32_t token = 0;
+  if (mPromiseIdToken.Get(aId, &token)) {
+    MOZ_ASSERT(mPendingSessions.Contains(token));
+    mPendingSessions.Remove(token);
+    mPromiseIdToken.Remove(aId);
+  }
+
+  MOZ_ASSERT(NS_FAILED(aExceptionCode));
+  promise->MaybeReject(aExceptionCode, aReason);
+
+  if (mCreatePromiseId == aId) {
+    // Note: This will probably destroy the MediaKeys object!
+    Release();
+  }
+}
+
+void
+MediaKeys::OnSessionIdReady(MediaKeySession* aSession)
+{
+  if (!aSession) {
+    NS_WARNING("Invalid MediaKeySession passed to OnSessionIdReady()");
+    return;
+  }
+  if (mKeySessions.Contains(aSession->GetSessionId())) {
+    NS_WARNING("MediaKeySession's made ready multiple times!");
+    return;
+  }
+  if (mPendingSessions.Contains(aSession->Token())) {
+    NS_WARNING("MediaKeySession made ready when it wasn't waiting to be ready!");
+    return;
+  }
+  if (aSession->GetSessionId().IsEmpty()) {
+    NS_WARNING("MediaKeySession with invalid sessionId passed to OnSessionIdReady()");
+    return;
+  }
+  mKeySessions.Put(aSession->GetSessionId(), aSession);
+}
+
+void
+MediaKeys::ResolvePromise(PromiseId aId)
+{
+  EME_LOG("MediaKeys[%p]::ResolvePromise(%d)", this, aId);
+
+  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
+  MOZ_ASSERT(!mPromises.Contains(aId));
+  if (!promise) {
+    return;
+  }
+
+  uint32_t token = 0;
+  if (!mPromiseIdToken.Get(aId, &token)) {
+    promise->MaybeResolveWithUndefined();
+    return;
+  } else if (!mPendingSessions.Contains(token)) {
+    // Pending session for CreateSession() should be removed when sessionId
+    // is ready.
+    promise->MaybeResolveWithUndefined();
+    mPromiseIdToken.Remove(aId);
+    return;
+  }
+  mPromiseIdToken.Remove(aId);
+
+  // We should only resolve LoadSession calls via this path,
+  // not CreateSession() promises.
+  RefPtr<MediaKeySession> session;
+  mPendingSessions.Remove(token, getter_AddRefs(session));
+  if (!session || session->GetSessionId().IsEmpty()) {
+    NS_WARNING("Received activation for non-existent session!");
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_ACCESS_ERR,
+                         NS_LITERAL_CSTRING("CDM LoadSession() returned a different session ID than requested"));
+    return;
+  }
+  mKeySessions.Put(session->GetSessionId(), session);
+  promise->MaybeResolve(session);
+}
+
+class MediaKeysGMPCrashHelper : public GMPCrashHelper
+{
+public:
+  explicit MediaKeysGMPCrashHelper(MediaKeys* aMediaKeys)
+    : mMediaKeys(aMediaKeys)
+  {
+    MOZ_ASSERT(NS_IsMainThread()); // WeakPtr isn't thread safe.
+  }
+  already_AddRefed<nsPIDOMWindowInner>
+  GetPluginCrashedEventTarget() override
+  {
+    MOZ_ASSERT(NS_IsMainThread()); // WeakPtr isn't thread safe.
+    EME_LOG("MediaKeysGMPCrashHelper::GetPluginCrashedEventTarget()");
+    return (mMediaKeys && mMediaKeys->GetParentObject()) ?
+      do_AddRef(mMediaKeys->GetParentObject()) : nullptr;
+  }
+private:
+  WeakPtr<MediaKeys> mMediaKeys;
+};
+
+already_AddRefed<CDMProxy>
+MediaKeys::CreateCDMProxy()
+{
+  RefPtr<CDMProxy> proxy;
+#ifdef MOZ_WIDGET_ANDROID
+  if (IsWidevineKeySystem(mKeySystem)) {
+    proxy = new MediaDrmCDMProxy(this,
+                                 mKeySystem,
+                                 mConfig.mDistinctiveIdentifier == MediaKeysRequirement::Required,
+                                 mConfig.mPersistentState == MediaKeysRequirement::Required);
+  } else
+#endif
+  {
+    proxy = new GMPCDMProxy(this,
+                            mKeySystem,
+                            new MediaKeysGMPCrashHelper(this),
+                            mConfig.mDistinctiveIdentifier == MediaKeysRequirement::Required,
+                            mConfig.mPersistentState == MediaKeysRequirement::Required);
+  }
+  return proxy.forget();
+}
+
+already_AddRefed<DetailedPromise>
+MediaKeys::Init(ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeys::Init()")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  mProxy = CreateCDMProxy();
+
+  // Determine principal (at creation time) of the MediaKeys object.
+  nsCOMPtr<nsIScriptObjectPrincipal> sop = do_QueryInterface(GetParentObject());
+  if (!sop) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Couldn't get script principal in MediaKeys::Init"));
+    return promise.forget();
+  }
+  mPrincipal = sop->GetPrincipal();
+
+  // Determine principal of the "top-level" window; the principal of the
+  // page that will display in the URL bar.
+  nsCOMPtr<nsPIDOMWindowInner> window = GetParentObject();
+  if (!window) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Couldn't get top-level window in MediaKeys::Init"));
+    return promise.forget();
+  }
+  nsCOMPtr<nsPIDOMWindowOuter> top = window->GetOuterWindow()->GetTop();
+  if (!top || !top->GetExtantDoc()) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Couldn't get document in MediaKeys::Init"));
+    return promise.forget();
+  }
+
+  mTopLevelPrincipal = top->GetExtantDoc()->NodePrincipal();
+
+  if (!mPrincipal || !mTopLevelPrincipal) {
+    NS_WARNING("Failed to get principals when creating MediaKeys");
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Couldn't get principal(s) in MediaKeys::Init"));
+    return promise.forget();
+  }
+
+  nsAutoCString origin;
+  nsresult rv = mPrincipal->GetOrigin(origin);
+  if (NS_FAILED(rv)) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Couldn't get principal origin string in MediaKeys::Init"));
+    return promise.forget();
+  }
+  nsAutoCString topLevelOrigin;
+  rv = mTopLevelPrincipal->GetOrigin(topLevelOrigin);
+  if (NS_FAILED(rv)) {
+    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                         NS_LITERAL_CSTRING("Couldn't get top-level principal origin string in MediaKeys::Init"));
+    return promise.forget();
+  }
+
+  nsIDocument* doc = window->GetExtantDoc();
+  const bool inPrivateBrowsing = nsContentUtils::IsInPrivateBrowsing(doc);
+
+  EME_LOG("MediaKeys[%p]::Create() (%s, %s), %s",
+          this,
+          origin.get(),
+          topLevelOrigin.get(),
+          (inPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"));
+
+  // The CDMProxy's initialization is asynchronous. The MediaKeys is
+  // refcounted, and its instance is returned to JS by promise once
+  // it's been initialized. No external refs exist to the MediaKeys while
+  // we're waiting for the promise to be resolved, so we must hold a
+  // reference to the new MediaKeys object until it's been created,
+  // or its creation has failed. Store the id of the promise returned
+  // here, and hold a self-reference until that promise is resolved or
+  // rejected.
+  MOZ_ASSERT(!mCreatePromiseId, "Should only be created once!");
+  mCreatePromiseId = StorePromise(promise);
+  AddRef();
+  mProxy->Init(mCreatePromiseId,
+               NS_ConvertUTF8toUTF16(origin),
+               NS_ConvertUTF8toUTF16(topLevelOrigin),
+               KeySystemToGMPName(mKeySystem),
+               inPrivateBrowsing);
+
+  return promise.forget();
+}
+
+void
+MediaKeys::OnCDMCreated(PromiseId aId, const nsACString& aNodeId, const uint32_t aPluginId)
+{
+  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
+  if (!promise) {
+    return;
+  }
+  mNodeId = aNodeId;
+  RefPtr<MediaKeys> keys(this);
+  EME_LOG("MediaKeys[%p]::OnCDMCreated() resolve promise id=%d", this, aId);
+  promise->MaybeResolve(keys);
+  if (mCreatePromiseId == aId) {
+    Release();
+  }
+
+  MediaKeySystemAccess::NotifyObservers(mParent,
+                                        mKeySystem,
+                                        MediaKeySystemStatus::Cdm_created);
+
+  Telemetry::Accumulate(Telemetry::VIDEO_CDM_CREATED, ToCDMTypeTelemetryEnum(mKeySystem));
+}
+
+static bool
+IsSessionTypeSupported(const MediaKeySessionType aSessionType,
+                       const MediaKeySystemConfiguration& aConfig)
+{
+  if (aSessionType == MediaKeySessionType::Temporary) {
+    // Temporary is always supported.
+    return true;
+  }
+  if (!aConfig.mSessionTypes.WasPassed()) {
+    // No other session types supported.
+    return false;
+  }
+  using MediaKeySessionTypeValues::strings;
+  const char* sessionType = strings[static_cast<uint32_t>(aSessionType)].value;
+  for (const nsString& s : aConfig.mSessionTypes.Value()) {
+    if (s.EqualsASCII(sessionType)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+already_AddRefed<MediaKeySession>
+MediaKeys::CreateSession(JSContext* aCx,
+                         MediaKeySessionType aSessionType,
+                         ErrorResult& aRv)
+{
+  if (!IsSessionTypeSupported(aSessionType, mConfig)) {
+    EME_LOG("MediaKeys[%p,'%s'] CreateSession() failed, unsupported session type", this);
+    aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+    return nullptr;
+  }
+
+  if (!mProxy) {
+    NS_WARNING("Tried to use a MediaKeys which lost its CDM");
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return nullptr;
+  }
+
+  EME_LOG("MediaKeys[%p] Creating session", this);
+
+  RefPtr<MediaKeySession> session = new MediaKeySession(aCx,
+                                                        GetParentObject(),
+                                                        this,
+                                                        mKeySystem,
+                                                        aSessionType,
+                                                        aRv);
+
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  // Add session to the set of sessions awaiting their sessionId being ready.
+  mPendingSessions.Put(session->Token(), session);
+
+  return session.forget();
+}
+
+void
+MediaKeys::OnSessionLoaded(PromiseId aId, bool aSuccess)
+{
+  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
+  if (!promise) {
+    return;
+  }
+  EME_LOG("MediaKeys[%p]::OnSessionLoaded() resolve promise id=%d", this, aId);
+
+  promise->MaybeResolve(aSuccess);
+}
+
+void
+MediaKeys::OnSessionClosed(MediaKeySession* aSession)
+{
+  nsAutoString id;
+  aSession->GetSessionId(id);
+  mKeySessions.Remove(id);
+}
+
+already_AddRefed<MediaKeySession>
+MediaKeys::GetSession(const nsAString& aSessionId)
+{
+  RefPtr<MediaKeySession> session;
+  mKeySessions.Get(aSessionId, getter_AddRefs(session));
+  return session.forget();
+}
+
+already_AddRefed<MediaKeySession>
+MediaKeys::GetPendingSession(uint32_t aToken)
+{
+  RefPtr<MediaKeySession> session;
+  mPendingSessions.Get(aToken, getter_AddRefs(session));
+  mPendingSessions.Remove(aToken);
+  return session.forget();
+}
+
+const nsCString&
+MediaKeys::GetNodeId() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mNodeId;
+}
+
+bool
+MediaKeys::IsBoundToMediaElement() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mElement != nullptr;
+}
+
+nsresult
+MediaKeys::Bind(HTMLMediaElement* aElement)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (IsBoundToMediaElement()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mElement = aElement;
+
+  return NS_OK;
+}
+
+void
+MediaKeys::Unbind()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mElement = nullptr;
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/media/eme/MediaKeys.h b/dom/media/eme/MediaKeys.h
new file mode 100644
index 0000000000..a3dbf37df2
--- /dev/null
+++ b/dom/media/eme/MediaKeys.h
@@ -0,0 +1,168 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_mediakeys_h__
+#define mozilla_dom_mediakeys_h__
+
+#include "nsWrapperCache.h"
+#include "nsISupports.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/RefPtr.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsRefPtrHashtable.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/MediaKeysBinding.h"
+#include "mozilla/dom/MediaKeySystemAccessBinding.h"
+#include "mozIGeckoMediaPluginService.h"
+#include "mozilla/DetailedPromise.h"
+#include "mozilla/WeakPtr.h"
+
+namespace mozilla {
+
+class CDMProxy;
+
+namespace dom {
+
+class ArrayBufferViewOrArrayBuffer;
+class MediaKeySession;
+class HTMLMediaElement;
+
+typedef nsRefPtrHashtable<nsStringHashKey, MediaKeySession> KeySessionHashMap;
+typedef nsRefPtrHashtable<nsUint32HashKey, dom::DetailedPromise> PromiseHashMap;
+typedef nsRefPtrHashtable<nsUint32HashKey, MediaKeySession> PendingKeySessionsHashMap;
+typedef nsDataHashtable<nsUint32HashKey, uint32_t> PendingPromiseIdTokenHashMap;
+typedef uint32_t PromiseId;
+
+// This class is used on the main thread only.
+// Note: its addref/release is not (and can't be) thread safe!
+class MediaKeys final : public nsISupports,
+                        public nsWrapperCache,
+                        public SupportsWeakPtr<MediaKeys>
+{
+  ~MediaKeys();
+
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaKeys)
+  MOZ_DECLARE_WEAKREFERENCE_TYPENAME(MediaKeys)
+
+  MediaKeys(nsPIDOMWindowInner* aParentWindow,
+            const nsAString& aKeySystem,
+            const MediaKeySystemConfiguration& aConfig);
+
+  already_AddRefed<DetailedPromise> Init(ErrorResult& aRv);
+
+  nsPIDOMWindowInner* GetParentObject() const;
+
+  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  nsresult Bind(HTMLMediaElement* aElement);
+  void Unbind();
+
+  // Javascript: readonly attribute DOMString keySystem;
+  void GetKeySystem(nsString& retval) const;
+
+  // JavaScript: MediaKeys.createSession()
+  already_AddRefed<MediaKeySession> CreateSession(JSContext* aCx,
+                                                  MediaKeySessionType aSessionType,
+                                                  ErrorResult& aRv);
+
+  // JavaScript: MediaKeys.SetServerCertificate()
+  already_AddRefed<DetailedPromise>
+    SetServerCertificate(const ArrayBufferViewOrArrayBuffer& aServerCertificate,
+                         ErrorResult& aRv);
+
+  already_AddRefed<MediaKeySession> GetSession(const nsAString& aSessionId);
+
+  // Removes and returns MediaKeySession from the set of sessions awaiting
+  // their sessionId to be assigned.
+  already_AddRefed<MediaKeySession> GetPendingSession(uint32_t aToken);
+
+  // Called once a Init() operation succeeds.
+  void OnCDMCreated(PromiseId aId,
+                    const nsACString& aNodeId, const uint32_t aPluginId);
+
+  // Called once the CDM generates a sessionId while servicing a
+  // MediaKeySession.generateRequest() or MediaKeySession.load() call,
+  // once the sessionId of a MediaKeySession is known.
+  void OnSessionIdReady(MediaKeySession* aSession);
+
+  // Called once a LoadSession succeeds.
+  void OnSessionLoaded(PromiseId aId, bool aSuccess);
+
+  // Called once a session has closed.
+  void OnSessionClosed(MediaKeySession* aSession);
+
+  CDMProxy* GetCDMProxy() { return mProxy; }
+
+  // Makes a new promise, or nullptr on failure.
+  already_AddRefed<DetailedPromise> MakePromise(ErrorResult& aRv,
+                                                const nsACString& aName);
+  // Stores promise in mPromises, returning an ID that can be used to retrieve
+  // it later. The ID is passed to the CDM, so that it can signal specific
+  // promises to be resolved.
+  PromiseId StorePromise(DetailedPromise* aPromise);
+
+  // Stores a map from promise id to pending session token. Using this
+  // mapping, when a promise is rejected via its ID, we can check if the
+  // promise corresponds to a pending session and retrieve that session
+  // via the mapped-to token, and remove the pending session from the
+  // list of sessions awaiting a session id.
+  void ConnectPendingPromiseIdWithToken(PromiseId aId, uint32_t aToken);
+
+  // Reject promise with DOMException corresponding to aExceptionCode.
+  void RejectPromise(PromiseId aId, nsresult aExceptionCode,
+                     const nsCString& aReason);
+  // Resolves promise with "undefined".
+  void ResolvePromise(PromiseId aId);
+
+  const nsCString& GetNodeId() const;
+
+  void Shutdown();
+
+  // Called by CDMProxy when CDM crashes or shuts down. It is different from
+  // Shutdown which is called from the script/dom side.
+  void Terminated();
+
+  // Returns true if this MediaKeys has been bound to a media element.
+  bool IsBoundToMediaElement() const;
+
+private:
+
+  // Instantiate CDMProxy instance.
+  // It could be MediaDrmCDMProxy (Widevine on Fennec) or GMPCDMProxy (the rest).
+  already_AddRefed<CDMProxy> CreateCDMProxy();
+
+  // Removes promise from mPromises, and returns it.
+  already_AddRefed<DetailedPromise> RetrievePromise(PromiseId aId);
+
+  // Owning ref to proxy. The proxy has a weak reference back to the MediaKeys,
+  // and the MediaKeys destructor clears the proxy's reference to the MediaKeys.
+  RefPtr<CDMProxy> mProxy;
+
+  RefPtr<HTMLMediaElement> mElement;
+
+  nsCOMPtr<nsPIDOMWindowInner> mParent;
+  const nsString mKeySystem;
+  nsCString mNodeId;
+  KeySessionHashMap mKeySessions;
+  PromiseHashMap mPromises;
+  PendingKeySessionsHashMap mPendingSessions;
+  PromiseId mCreatePromiseId;
+
+  RefPtr<nsIPrincipal> mPrincipal;
+  RefPtr<nsIPrincipal> mTopLevelPrincipal;
+
+  const MediaKeySystemConfiguration mConfig;
+
+  PendingPromiseIdTokenHashMap mPromiseIdToken;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_mediakeys_h__
diff --git a/dom/media/eme/mediadrm/MediaDrmCDMCallbackProxy.cpp b/dom/media/eme/mediadrm/MediaDrmCDMCallbackProxy.cpp
new file mode 100644
index 0000000000..ee57afae93
--- /dev/null
+++ b/dom/media/eme/mediadrm/MediaDrmCDMCallbackProxy.cpp
@@ -0,0 +1,140 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaDrmCDMCallbackProxy.h"
+#include "mozilla/CDMProxy.h"
+#include "nsString.h"
+#include "mozilla/dom/MediaKeys.h"
+#include "mozilla/dom/MediaKeySession.h"
+#include "mozIGeckoMediaPluginService.h"
+#include "nsContentCID.h"
+#include "nsServiceManagerUtils.h"
+#include "MainThreadUtils.h"
+#include "mozilla/EMEUtils.h"
+
+namespace mozilla {
+
+MediaDrmCDMCallbackProxy::MediaDrmCDMCallbackProxy(CDMProxy* aProxy)
+  : mProxy(aProxy)
+{
+
+}
+
+void
+MediaDrmCDMCallbackProxy::SetSessionId(uint32_t aToken,
+                                       const nsCString& aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mProxy->OnSetSessionId(aToken, NS_ConvertUTF8toUTF16(aSessionId));
+}
+
+void
+MediaDrmCDMCallbackProxy::ResolveLoadSessionPromise(uint32_t aPromiseId,
+                                                    bool aSuccess)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mProxy->OnResolveLoadSessionPromise(aPromiseId, aSuccess);
+}
+
+void
+MediaDrmCDMCallbackProxy::ResolvePromise(uint32_t aPromiseId)
+{
+  // Note: CDMProxy proxies this from non-main threads to main thread.
+  mProxy->ResolvePromise(aPromiseId);
+}
+
+void
+MediaDrmCDMCallbackProxy::RejectPromise(uint32_t aPromiseId,
+                                        nsresult aException,
+                                        const nsCString& aMessage)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mProxy->OnRejectPromise(aPromiseId, aException, aMessage);
+}
+
+void
+MediaDrmCDMCallbackProxy::SessionMessage(const nsCString& aSessionId,
+                                         dom::MediaKeyMessageType aMessageType,
+                                         const nsTArray<uint8_t>& aMessage)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  // For removing constness
+  nsTArray<uint8_t> message(aMessage);
+  mProxy->OnSessionMessage(NS_ConvertUTF8toUTF16(aSessionId), aMessageType, message);
+}
+
+void
+MediaDrmCDMCallbackProxy::ExpirationChange(const nsCString& aSessionId,
+                                           UnixTime aExpiryTime)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mProxy->OnExpirationChange(NS_ConvertUTF8toUTF16(aSessionId), aExpiryTime);
+}
+
+void
+MediaDrmCDMCallbackProxy::SessionClosed(const nsCString& aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  bool keyStatusesChange = false;
+  {
+    CDMCaps::AutoLock caps(mProxy->Capabilites());
+    keyStatusesChange = caps.RemoveKeysForSession(NS_ConvertUTF8toUTF16(aSessionId));
+  }
+  if (keyStatusesChange) {
+    mProxy->OnKeyStatusesChange(NS_ConvertUTF8toUTF16(aSessionId));
+  }
+  mProxy->OnSessionClosed(NS_ConvertUTF8toUTF16(aSessionId));
+}
+
+void
+MediaDrmCDMCallbackProxy::SessionError(const nsCString& aSessionId,
+                                       nsresult aException,
+                                       uint32_t aSystemCode,
+                                       const nsCString& aMessage)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mProxy->OnSessionError(NS_ConvertUTF8toUTF16(aSessionId),
+                         aException,
+                         aSystemCode,
+                         NS_ConvertUTF8toUTF16(aMessage));
+}
+
+void
+MediaDrmCDMCallbackProxy::BatchedKeyStatusChanged(const nsCString& aSessionId,
+                                                  const nsTArray<CDMKeyInfo>& aKeyInfos)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  BatchedKeyStatusChangedInternal(aSessionId, aKeyInfos);
+}
+
+void
+MediaDrmCDMCallbackProxy::BatchedKeyStatusChangedInternal(const nsCString& aSessionId,
+                                                          const nsTArray<CDMKeyInfo>& aKeyInfos)
+{
+  bool keyStatusesChange = false;
+  {
+    CDMCaps::AutoLock caps(mProxy->Capabilites());
+    for (size_t i = 0; i < aKeyInfos.Length(); i++) {
+      keyStatusesChange |=
+        caps.SetKeyStatus(aKeyInfos[i].mKeyId,
+                          NS_ConvertUTF8toUTF16(aSessionId),
+                          aKeyInfos[i].mStatus);
+    }
+  }
+  if (keyStatusesChange) {
+    mProxy->OnKeyStatusesChange(NS_ConvertUTF8toUTF16(aSessionId));
+  }
+}
+
+void
+MediaDrmCDMCallbackProxy::Decrypted(uint32_t aId,
+                                    DecryptStatus aResult,
+                                    const nsTArray<uint8_t>& aDecryptedData)
+{
+  MOZ_ASSERT_UNREACHABLE("Fennec could not handle decrypted event");
+}
+
+} // namespace mozilla
\ No newline at end of file
diff --git a/dom/media/eme/mediadrm/MediaDrmCDMCallbackProxy.h b/dom/media/eme/mediadrm/MediaDrmCDMCallbackProxy.h
new file mode 100644
index 0000000000..29f9c81922
--- /dev/null
+++ b/dom/media/eme/mediadrm/MediaDrmCDMCallbackProxy.h
@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MediaDrmCDMCallbackProxy_h_
+#define MediaDrmCDMCallbackProxy_h_
+
+#include "mozilla/CDMProxy.h"
+#include "mozilla/DecryptorProxyCallback.h"
+
+namespace mozilla {
+class CDMProxy;
+// Proxies call backs from the MediaDrmProxy -> MediaDrmProxySupport back to the MediaKeys
+// object on the main thread.
+// We used annotation calledFrom = "gecko" to ensure running on main thread.
+class MediaDrmCDMCallbackProxy : public DecryptorProxyCallback {
+public:
+
+  void SetDecryptorId(uint32_t aId) override {}
+
+  void SetSessionId(uint32_t aCreateSessionToken,
+                    const nsCString& aSessionId) override;
+
+  void ResolveLoadSessionPromise(uint32_t aPromiseId,
+                                 bool aSuccess) override;
+
+  void ResolvePromise(uint32_t aPromiseId) override;
+
+  void RejectPromise(uint32_t aPromiseId,
+                     nsresult aException,
+                     const nsCString& aSessionId) override;
+
+  void SessionMessage(const nsCString& aSessionId,
+                      dom::MediaKeyMessageType aMessageType,
+                      const nsTArray<uint8_t>& aMessage) override;
+
+  void ExpirationChange(const nsCString& aSessionId,
+                        UnixTime aExpiryTime) override;
+
+  void SessionClosed(const nsCString& aSessionId) override;
+
+  void SessionError(const nsCString& aSessionId,
+                    nsresult aException,
+                    uint32_t aSystemCode,
+                    const nsCString& aMessage) override;
+
+  void Decrypted(uint32_t aId,
+                 DecryptStatus aResult,
+                 const nsTArray<uint8_t>& aDecryptedData) override;
+
+  void BatchedKeyStatusChanged(const nsCString& aSessionId,
+                               const nsTArray<CDMKeyInfo>& aKeyInfos) override;
+
+   ~MediaDrmCDMCallbackProxy() {}
+
+private:
+  friend class MediaDrmCDMProxy;
+  explicit MediaDrmCDMCallbackProxy(CDMProxy* aProxy);
+
+  void BatchedKeyStatusChangedInternal(const nsCString& aSessionId,
+                                       const nsTArray<CDMKeyInfo>& aKeyInfos);
+  // Warning: Weak ref.
+  CDMProxy* mProxy;
+};
+
+} // namespace mozilla
+#endif
\ No newline at end of file
diff --git a/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp b/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp
new file mode 100644
index 0000000000..a57d764e70
--- /dev/null
+++ b/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp
@@ -0,0 +1,467 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/MediaKeySession.h"
+#include "mozilla/MediaDrmCDMProxy.h"
+#include "MediaDrmCDMCallbackProxy.h"
+
+using namespace mozilla::java::sdk;
+
+namespace mozilla {
+
+MediaDrmSessionType
+ToMediaDrmSessionType(dom::MediaKeySessionType aSessionType)
+{
+  switch (aSessionType) {
+    case dom::MediaKeySessionType::Temporary: return kKeyStreaming;
+    case dom::MediaKeySessionType::Persistent_license: return kKeyOffline;
+    default: return kKeyStreaming;
+  };
+}
+
+MediaDrmCDMProxy::MediaDrmCDMProxy(dom::MediaKeys* aKeys,
+                                   const nsAString& aKeySystem,
+                                   bool aDistinctiveIdentifierRequired,
+                                   bool aPersistentStateRequired)
+  : CDMProxy(aKeys,
+             aKeySystem,
+             aDistinctiveIdentifierRequired,
+             aPersistentStateRequired)
+  , mCDM(nullptr)
+  , mShutdownCalled(false)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_COUNT_CTOR(MediaDrmCDMProxy);
+}
+
+MediaDrmCDMProxy::~MediaDrmCDMProxy()
+{
+  MOZ_COUNT_DTOR(MediaDrmCDMProxy);
+}
+
+void
+MediaDrmCDMProxy::Init(PromiseId aPromiseId,
+                       const nsAString& aOrigin,
+                       const nsAString& aTopLevelOrigin,
+                       const nsAString& aName,
+                       bool aInPrivateBrowsing)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
+
+  EME_LOG("MediaDrmCDMProxy::Init (%s, %s) %s",
+          NS_ConvertUTF16toUTF8(aOrigin).get(),
+          NS_ConvertUTF16toUTF8(aTopLevelOrigin).get(),
+          (aInPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"));
+
+  // Create a thread to work with cdm.
+  if (!mOwnerThread) {
+    nsresult rv = NS_NewNamedThread("MDCDMThread", getter_AddRefs(mOwnerThread));
+    if (NS_FAILED(rv)) {
+      RejectPromise(aPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                    NS_LITERAL_CSTRING("Couldn't create CDM thread MediaDrmCDMProxy::Init"));
+      return;
+    }
+  }
+
+  mCDM = mozilla::MakeUnique<MediaDrmProxySupport>(mKeySystem);
+  nsCOMPtr<nsIRunnable> task(NewRunnableMethod<uint32_t>(this,
+                                                         &MediaDrmCDMProxy::md_Init,
+                                                         aPromiseId));
+  mOwnerThread->Dispatch(task, NS_DISPATCH_NORMAL);
+}
+
+void
+MediaDrmCDMProxy::CreateSession(uint32_t aCreateSessionToken,
+                                MediaKeySessionType aSessionType,
+                                PromiseId aPromiseId,
+                                const nsAString& aInitDataType,
+                                nsTArray<uint8_t>& aInitData)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mOwnerThread);
+
+  nsAutoPtr<CreateSessionData> data(new CreateSessionData());
+  data->mSessionType = aSessionType;
+  data->mCreateSessionToken = aCreateSessionToken;
+  data->mPromiseId = aPromiseId;
+  data->mInitDataType = NS_ConvertUTF16toUTF8(aInitDataType);
+  data->mInitData = Move(aInitData);
+
+  nsCOMPtr<nsIRunnable> task(
+    NewRunnableMethod<nsAutoPtr<CreateSessionData>>(this,
+                                                    &MediaDrmCDMProxy::md_CreateSession,
+                                                    data));
+  mOwnerThread->Dispatch(task, NS_DISPATCH_NORMAL);
+}
+
+void
+MediaDrmCDMProxy::LoadSession(PromiseId aPromiseId,
+                              const nsAString& aSessionId)
+{
+  // TODO: Implement LoadSession.
+  RejectPromise(aPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                NS_LITERAL_CSTRING("Currently Fennec did not support LoadSession"));
+}
+
+void
+MediaDrmCDMProxy::SetServerCertificate(PromiseId aPromiseId,
+                                     nsTArray<uint8_t>& aCert)
+{
+  // TODO: Implement SetServerCertificate.
+  RejectPromise(aPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                NS_LITERAL_CSTRING("Currently Fennec did not support SetServerCertificate"));
+}
+
+void
+MediaDrmCDMProxy::UpdateSession(const nsAString& aSessionId,
+                              PromiseId aPromiseId,
+                              nsTArray<uint8_t>& aResponse)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mOwnerThread);
+  NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
+
+  nsAutoPtr<UpdateSessionData> data(new UpdateSessionData());
+  data->mPromiseId = aPromiseId;
+  data->mSessionId = NS_ConvertUTF16toUTF8(aSessionId);
+  data->mResponse = Move(aResponse);
+
+  nsCOMPtr<nsIRunnable> task(
+    NewRunnableMethod<nsAutoPtr<UpdateSessionData>>(this,
+                                                    &MediaDrmCDMProxy::md_UpdateSession,
+                                                    data));
+  mOwnerThread->Dispatch(task, NS_DISPATCH_NORMAL);
+}
+
+void
+MediaDrmCDMProxy::CloseSession(const nsAString& aSessionId,
+                             PromiseId aPromiseId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mOwnerThread);
+  NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
+
+  nsAutoPtr<SessionOpData> data(new SessionOpData());
+  data->mPromiseId = aPromiseId;
+  data->mSessionId = NS_ConvertUTF16toUTF8(aSessionId);
+
+  nsCOMPtr<nsIRunnable> task(
+    NewRunnableMethod<nsAutoPtr<SessionOpData>>(this,
+                                                &MediaDrmCDMProxy::md_CloseSession,
+                                                data));
+  mOwnerThread->Dispatch(task, NS_DISPATCH_NORMAL);
+}
+
+void
+MediaDrmCDMProxy::RemoveSession(const nsAString& aSessionId,
+                              PromiseId aPromiseId)
+{
+  // TODO: Implement RemoveSession.
+  RejectPromise(aPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                NS_LITERAL_CSTRING("Currently Fennec did not support RemoveSession"));
+}
+
+void
+MediaDrmCDMProxy::Shutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mOwnerThread);
+  nsCOMPtr<nsIRunnable> task(
+    NewRunnableMethod(this, &MediaDrmCDMProxy::md_Shutdown));
+
+  mOwnerThread->Dispatch(task, NS_DISPATCH_NORMAL);
+  mOwnerThread->Shutdown();
+  mOwnerThread = nullptr;
+}
+
+void
+MediaDrmCDMProxy::Terminated()
+{
+  // TODO: Implement Terminated.
+  // Should find a way to handle the case when remote side MediaDrm crashed.
+}
+
+const nsCString&
+MediaDrmCDMProxy::GetNodeId() const
+{
+  return mNodeId;
+}
+
+void
+MediaDrmCDMProxy::OnSetSessionId(uint32_t aCreateSessionToken,
+                                 const nsAString& aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+
+  RefPtr<dom::MediaKeySession> session(mKeys->GetPendingSession(aCreateSessionToken));
+  if (session) {
+    session->SetSessionId(aSessionId);
+  }
+}
+
+void
+MediaDrmCDMProxy::OnResolveLoadSessionPromise(uint32_t aPromiseId, bool aSuccess)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  mKeys->OnSessionLoaded(aPromiseId, aSuccess);
+}
+
+void
+MediaDrmCDMProxy::OnSessionMessage(const nsAString& aSessionId,
+                                   dom::MediaKeyMessageType aMessageType,
+                                   nsTArray<uint8_t>& aMessage)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  RefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
+  if (session) {
+    session->DispatchKeyMessage(aMessageType, aMessage);
+  }
+}
+
+void
+MediaDrmCDMProxy::OnExpirationChange(const nsAString& aSessionId,
+                                     UnixTime aExpiryTime)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  RefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
+  if (session) {
+    session->SetExpiration(static_cast<double>(aExpiryTime));
+  }
+}
+
+void
+MediaDrmCDMProxy::OnSessionClosed(const nsAString& aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  RefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
+  if (session) {
+    session->OnClosed();
+  }
+}
+
+void
+MediaDrmCDMProxy::OnSessionError(const nsAString& aSessionId,
+                                 nsresult aException,
+                                 uint32_t aSystemCode,
+                                 const nsAString& aMsg)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  RefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
+  if (session) {
+    session->DispatchKeyError(aSystemCode);
+  }
+}
+
+void
+MediaDrmCDMProxy::OnRejectPromise(uint32_t aPromiseId,
+                                  nsresult aDOMException,
+                                  const nsCString& aMsg)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  RejectPromise(aPromiseId, aDOMException, aMsg);
+}
+
+RefPtr<MediaDrmCDMProxy::DecryptPromise>
+MediaDrmCDMProxy::Decrypt(MediaRawData* aSample)
+{
+  MOZ_ASSERT_UNREACHABLE("Fennec could not handle decrypting individually");
+  return nullptr;
+}
+
+void
+MediaDrmCDMProxy::OnDecrypted(uint32_t aId,
+                              DecryptStatus aResult,
+                              const nsTArray<uint8_t>& aDecryptedData)
+{
+  MOZ_ASSERT_UNREACHABLE("Fennec could not handle decrypted event");
+}
+
+void
+MediaDrmCDMProxy::RejectPromise(PromiseId aId, nsresult aCode,
+                                const nsCString& aReason)
+{
+  if (NS_IsMainThread()) {
+    if (!mKeys.IsNull()) {
+      mKeys->RejectPromise(aId, aCode, aReason);
+    }
+  } else {
+    nsCOMPtr<nsIRunnable> task(new RejectPromiseTask(this, aId, aCode,
+                                                     aReason));
+    NS_DispatchToMainThread(task);
+  }
+}
+
+void
+MediaDrmCDMProxy::ResolvePromise(PromiseId aId)
+{
+  if (NS_IsMainThread()) {
+    if (!mKeys.IsNull()) {
+      mKeys->ResolvePromise(aId);
+    } else {
+      NS_WARNING("MediaDrmCDMProxy unable to resolve promise!");
+    }
+  } else {
+    nsCOMPtr<nsIRunnable> task;
+    task = NewRunnableMethod<PromiseId>(this,
+                                        &MediaDrmCDMProxy::ResolvePromise,
+                                        aId);
+    NS_DispatchToMainThread(task);
+  }
+}
+
+const nsString&
+MediaDrmCDMProxy::KeySystem() const
+{
+  return mKeySystem;
+}
+
+CDMCaps&
+MediaDrmCDMProxy::Capabilites()
+{
+  return mCapabilites;
+}
+
+void
+MediaDrmCDMProxy::OnKeyStatusesChange(const nsAString& aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  RefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
+  if (session) {
+    session->DispatchKeyStatusesChange();
+  }
+}
+
+void
+MediaDrmCDMProxy::GetSessionIdsForKeyId(const nsTArray<uint8_t>& aKeyId,
+                                      nsTArray<nsCString>& aSessionIds)
+{
+  CDMCaps::AutoLock caps(Capabilites());
+  caps.GetSessionIdsForKeyId(aKeyId, aSessionIds);
+}
+
+#ifdef DEBUG
+bool
+MediaDrmCDMProxy::IsOnOwnerThread()
+{
+  return NS_GetCurrentThread() == mOwnerThread;
+}
+#endif
+
+void
+MediaDrmCDMProxy::OnCDMCreated(uint32_t aPromiseId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+
+  if (mCDM) {
+    mKeys->OnCDMCreated(aPromiseId, GetNodeId(), 0);
+    return;
+  }
+
+  // No CDM? Just reject the promise.
+  mKeys->RejectPromise(aPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                       NS_LITERAL_CSTRING("Null CDM in OnCDMCreated()"));
+}
+
+void
+MediaDrmCDMProxy::md_Init(uint32_t aPromiseId)
+{
+  MOZ_ASSERT(IsOnOwnerThread());
+  MOZ_ASSERT(mCDM);
+
+  mCallback = new MediaDrmCDMCallbackProxy(this);
+  mCDM->Init(mCallback);
+  nsCOMPtr<nsIRunnable> task(
+    NewRunnableMethod<uint32_t>(this,
+                                &MediaDrmCDMProxy::OnCDMCreated,
+                                aPromiseId));
+  NS_DispatchToMainThread(task);
+}
+
+void
+MediaDrmCDMProxy::md_CreateSession(nsAutoPtr<CreateSessionData> aData)
+{
+  MOZ_ASSERT(IsOnOwnerThread());
+
+  if (!mCDM) {
+    RejectPromise(aData->mPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                  NS_LITERAL_CSTRING("Null CDM in md_CreateSession"));
+    return;
+  }
+
+  mCDM->CreateSession(aData->mCreateSessionToken,
+                      aData->mPromiseId,
+                      aData->mInitDataType,
+                      aData->mInitData,
+                      ToMediaDrmSessionType(aData->mSessionType));
+}
+
+void
+MediaDrmCDMProxy::md_UpdateSession(nsAutoPtr<UpdateSessionData> aData)
+{
+  MOZ_ASSERT(IsOnOwnerThread());
+
+  if (!mCDM) {
+    RejectPromise(aData->mPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                  NS_LITERAL_CSTRING("Null CDM in md_UpdateSession"));
+    return;
+  }
+  mCDM->UpdateSession(aData->mPromiseId,
+                      aData->mSessionId,
+                      aData->mResponse);
+}
+
+void
+MediaDrmCDMProxy::md_CloseSession(nsAutoPtr<SessionOpData> aData)
+{
+  MOZ_ASSERT(IsOnOwnerThread());
+
+  if (!mCDM) {
+    RejectPromise(aData->mPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
+                  NS_LITERAL_CSTRING("Null CDM in md_CloseSession"));
+    return;
+  }
+  mCDM->CloseSession(aData->mPromiseId, aData->mSessionId);
+}
+
+void
+MediaDrmCDMProxy::md_Shutdown()
+{
+  MOZ_ASSERT(IsOnOwnerThread());
+  MOZ_ASSERT(mCDM);
+  if (mShutdownCalled) {
+    return;
+  }
+  mShutdownCalled = true;
+  mCDM->Shutdown();
+  mCDM = nullptr;
+}
+
+} // namespace mozilla
\ No newline at end of file
diff --git a/dom/media/eme/mediadrm/MediaDrmCDMProxy.h b/dom/media/eme/mediadrm/MediaDrmCDMProxy.h
new file mode 100644
index 0000000000..c7cb3000f0
--- /dev/null
+++ b/dom/media/eme/mediadrm/MediaDrmCDMProxy.h
@@ -0,0 +1,184 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MediaDrmCDMProxy_h_
+#define MediaDrmCDMProxy_h_
+
+#include <jni.h>
+#include "mozilla/jni/Types.h"
+#include "GeneratedJNINatives.h"
+
+#include "mozilla/CDMProxy.h"
+#include "mozilla/CDMCaps.h"
+#include "mozilla/dom/MediaKeys.h"
+#include "mozilla/MediaDrmProxySupport.h"
+#include "mozilla/UniquePtr.h"
+
+#include "MediaCodec.h"
+#include "nsString.h"
+#include "nsAutoPtr.h"
+
+using namespace mozilla::java;
+
+namespace mozilla {
+class MediaDrmCDMCallbackProxy;
+class MediaDrmCDMProxy : public CDMProxy {
+public:
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaDrmCDMProxy)
+
+  MediaDrmCDMProxy(dom::MediaKeys* aKeys,
+                   const nsAString& aKeySystem,
+                   bool aDistinctiveIdentifierRequired,
+                   bool aPersistentStateRequired);
+
+  void Init(PromiseId aPromiseId,
+            const nsAString& aOrigin,
+            const nsAString& aTopLevelOrigin,
+            const nsAString& aGMPName,
+            bool aInPrivateBrowsing) override;
+
+  void CreateSession(uint32_t aCreateSessionToken,
+                     MediaKeySessionType aSessionType,
+                     PromiseId aPromiseId,
+                     const nsAString& aInitDataType,
+                     nsTArray<uint8_t>& aInitData) override;
+
+  void LoadSession(PromiseId aPromiseId,
+                   const nsAString& aSessionId) override;
+
+  void SetServerCertificate(PromiseId aPromiseId,
+                            nsTArray<uint8_t>& aCert) override;
+
+  void UpdateSession(const nsAString& aSessionId,
+                     PromiseId aPromiseId,
+                     nsTArray<uint8_t>& aResponse) override;
+
+  void CloseSession(const nsAString& aSessionId,
+                    PromiseId aPromiseId) override;
+
+  void RemoveSession(const nsAString& aSessionId,
+                     PromiseId aPromiseId) override;
+
+  void Shutdown() override;
+
+  void Terminated() override;
+
+  const nsCString& GetNodeId() const override;
+
+  void OnSetSessionId(uint32_t aCreateSessionToken,
+                      const nsAString& aSessionId) override;
+
+  void OnResolveLoadSessionPromise(uint32_t aPromiseId, bool aSuccess) override;
+
+  void OnSessionMessage(const nsAString& aSessionId,
+                        dom::MediaKeyMessageType aMessageType,
+                        nsTArray<uint8_t>& aMessage) override;
+
+  void OnExpirationChange(const nsAString& aSessionId,
+                          UnixTime aExpiryTime) override;
+
+  void OnSessionClosed(const nsAString& aSessionId) override;
+
+  void OnSessionError(const nsAString& aSessionId,
+                      nsresult aException,
+                      uint32_t aSystemCode,
+                      const nsAString& aMsg) override;
+
+  void OnRejectPromise(uint32_t aPromiseId,
+                       nsresult aCode,
+                       const nsCString& aMsg) override;
+
+  RefPtr<DecryptPromise> Decrypt(MediaRawData* aSample) override;
+  void OnDecrypted(uint32_t aId,
+                   DecryptStatus aResult,
+                   const nsTArray<uint8_t>& aDecryptedData) override;
+
+  void RejectPromise(PromiseId aId, nsresult aCode,
+                     const nsCString& aReason) override;
+
+  // Resolves promise with "undefined".
+  // Can be called from any thread.
+  void ResolvePromise(PromiseId aId) override;
+
+  // Threadsafe.
+  const nsString& KeySystem() const override;
+
+  CDMCaps& Capabilites() override;
+
+  void OnKeyStatusesChange(const nsAString& aSessionId) override;
+
+  void GetSessionIdsForKeyId(const nsTArray<uint8_t>& aKeyId,
+                             nsTArray<nsCString>& aSessionIds) override;
+
+#ifdef DEBUG
+  bool IsOnOwnerThread() override;
+#endif
+
+private:
+  virtual ~MediaDrmCDMProxy();
+
+  void OnCDMCreated(uint32_t aPromiseId);
+
+  struct CreateSessionData {
+    MediaKeySessionType mSessionType;
+    uint32_t mCreateSessionToken;
+    PromiseId mPromiseId;
+    nsCString mInitDataType;
+    nsTArray<uint8_t> mInitData;
+  };
+
+  struct UpdateSessionData {
+    PromiseId mPromiseId;
+    nsCString mSessionId;
+    nsTArray<uint8_t> mResponse;
+  };
+
+  struct SessionOpData {
+    PromiseId mPromiseId;
+    nsCString mSessionId;
+  };
+
+  class RejectPromiseTask : public Runnable {
+  public:
+    RejectPromiseTask(MediaDrmCDMProxy* aProxy,
+                      PromiseId aId,
+                      nsresult aCode,
+                      const nsCString& aReason)
+      : mProxy(aProxy)
+      , mId(aId)
+      , mCode(aCode)
+      , mReason(aReason)
+    {
+    }
+    NS_METHOD Run() {
+      mProxy->RejectPromise(mId, mCode, mReason);
+      return NS_OK;
+    }
+  private:
+    RefPtr<MediaDrmCDMProxy> mProxy;
+    PromiseId mId;
+    nsresult mCode;
+    nsCString mReason;
+  };
+
+  nsCString mNodeId;
+  mozilla::UniquePtr<MediaDrmProxySupport> mCDM;
+  nsAutoPtr<MediaDrmCDMCallbackProxy> mCallback;
+  bool mShutdownCalled;
+
+// =====================================================================
+// For MediaDrmProxySupport
+  void md_Init(uint32_t aPromiseId);
+  void md_CreateSession(nsAutoPtr<CreateSessionData> aData);
+  void md_UpdateSession(nsAutoPtr<UpdateSessionData> aData);
+  void md_CloseSession(nsAutoPtr<SessionOpData> aData);
+  void md_Shutdown();
+// =====================================================================
+};
+
+} // namespace mozilla
+#endif // MediaDrmCDMProxy_h_
\ No newline at end of file
diff --git a/dom/media/eme/mediadrm/MediaDrmProxySupport.cpp b/dom/media/eme/mediadrm/MediaDrmProxySupport.cpp
new file mode 100644
index 0000000000..192769470e
--- /dev/null
+++ b/dom/media/eme/mediadrm/MediaDrmProxySupport.cpp
@@ -0,0 +1,284 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaDrmProxySupport.h"
+#include "mozilla/EMEUtils.h"
+#include "FennecJNINatives.h"
+#include "MediaCodec.h" // For MediaDrm::KeyStatus
+#include "MediaPrefs.h"
+
+using namespace mozilla::java;
+
+namespace mozilla {
+
+LogModule* GetMDRMNLog() {
+  static LazyLogModule log("MediaDrmProxySupport");
+  return log;
+}
+
+class MediaDrmJavaCallbacksSupport
+  : public MediaDrmProxy::NativeMediaDrmProxyCallbacks::Natives<MediaDrmJavaCallbacksSupport>
+{
+public:
+  typedef MediaDrmProxy::NativeMediaDrmProxyCallbacks::Natives<MediaDrmJavaCallbacksSupport> MediaDrmProxyNativeCallbacks;
+  using MediaDrmProxyNativeCallbacks::DisposeNative;
+  using MediaDrmProxyNativeCallbacks::AttachNative;
+
+  MediaDrmJavaCallbacksSupport(DecryptorProxyCallback* aDecryptorProxyCallback)
+    : mDecryptorProxyCallback(aDecryptorProxyCallback)
+  {
+    MOZ_ASSERT(aDecryptorProxyCallback);
+  }
+  /*
+   * Native implementation, called by Java.
+   */
+  void OnSessionCreated(int aCreateSessionToken,
+                        int aPromiseId,
+                        jni::ByteArray::Param aSessionId,
+                        jni::ByteArray::Param aRequest);
+
+  void OnSessionUpdated(int aPromiseId, jni::ByteArray::Param aSessionId);
+
+  void OnSessionClosed(int aPromiseId, jni::ByteArray::Param aSessionId);
+
+  void OnSessionMessage(jni::ByteArray::Param aSessionId,
+                        int /*mozilla::dom::MediaKeyMessageType*/ aSessionMessageType,
+                        jni::ByteArray::Param aRequest);
+
+  void OnSessionError(jni::ByteArray::Param aSessionId,
+                      jni::String::Param aMessage);
+
+  void OnSessionBatchedKeyChanged(jni::ByteArray::Param,
+                                  jni::ObjectArray::Param);
+
+  void OnRejectPromise(int aPromiseId, jni::String::Param aMessage);
+
+private:
+  DecryptorProxyCallback* mDecryptorProxyCallback;
+}; // MediaDrmJavaCallbacksSupport
+
+void
+MediaDrmJavaCallbacksSupport::OnSessionCreated(int aCreateSessionToken,
+                                               int aPromiseId,
+                                               jni::ByteArray::Param aSessionId,
+                                               jni::ByteArray::Param aRequest)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  auto reqDataArray = aRequest->GetElements();
+  nsCString sessionId(reinterpret_cast<char*>(aSessionId->GetElements().Elements()),
+                      aSessionId->Length());
+  MDRMN_LOG("SessionId(%s) closed", sessionId.get());
+
+  mDecryptorProxyCallback->SetSessionId(aCreateSessionToken, sessionId);
+  mDecryptorProxyCallback->ResolvePromise(aPromiseId);
+}
+
+void
+MediaDrmJavaCallbacksSupport::OnSessionUpdated(int aPromiseId,
+                                               jni::ByteArray::Param aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MDRMN_LOG("SessionId(%s) closed",
+            nsCString(reinterpret_cast<char*>(aSessionId->GetElements().Elements()),
+                      aSessionId->Length()).get());
+  mDecryptorProxyCallback->ResolvePromise(aPromiseId);
+}
+
+void
+MediaDrmJavaCallbacksSupport::OnSessionClosed(int aPromiseId,
+                                              jni::ByteArray::Param aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  nsCString sessionId(reinterpret_cast<char*>(aSessionId->GetElements().Elements()),
+                      aSessionId->Length());
+  MDRMN_LOG("SessionId(%s) closed", sessionId.get());
+  mDecryptorProxyCallback->ResolvePromise(aPromiseId);
+  mDecryptorProxyCallback->SessionClosed(sessionId);
+}
+
+void
+MediaDrmJavaCallbacksSupport::OnSessionMessage(jni::ByteArray::Param aSessionId,
+                                               int /*mozilla::dom::MediaKeyMessageType*/ aMessageType,
+                                               jni::ByteArray::Param aRequest)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  nsCString sessionId(reinterpret_cast<char*>(aSessionId->GetElements().Elements()),
+                      aSessionId->Length());
+  auto reqDataArray = aRequest->GetElements();
+
+  nsTArray<uint8_t> retRequest;
+  retRequest.AppendElements(reinterpret_cast<uint8_t*>(reqDataArray.Elements()),
+                            reqDataArray.Length());
+
+  mDecryptorProxyCallback->SessionMessage(sessionId,
+                                          static_cast<dom::MediaKeyMessageType>(aMessageType),
+                                          retRequest);
+}
+
+void
+MediaDrmJavaCallbacksSupport::OnSessionError(jni::ByteArray::Param aSessionId,
+                                             jni::String::Param aMessage)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  nsCString sessionId(reinterpret_cast<char*>(aSessionId->GetElements().Elements()),
+                      aSessionId->Length());
+  nsCString errorMessage = aMessage->ToCString();
+  MDRMN_LOG("SessionId(%s)", sessionId.get());
+  // TODO: We cannot get system error code from media drm API.
+  // Currently use -1 as an error code.
+  mDecryptorProxyCallback->SessionError(sessionId,
+                                        NS_ERROR_DOM_INVALID_STATE_ERR,
+                                        -1,
+                                        errorMessage);
+}
+
+// TODO: MediaDrm.KeyStatus defined the status code not included
+// dom::MediaKeyStatus::Released and dom::MediaKeyStatus::Output_downscaled.
+// Should keep tracking for this if it will be changed in the future.
+static dom::MediaKeyStatus
+MediaDrmKeyStatusToMediaKeyStatus(int aStatusCode)
+{
+  using mozilla::java::sdk::KeyStatus;
+  switch (aStatusCode) {
+    case KeyStatus::STATUS_USABLE: return dom::MediaKeyStatus::Usable;
+    case KeyStatus::STATUS_EXPIRED: return dom::MediaKeyStatus::Expired;
+    case KeyStatus::STATUS_OUTPUT_NOT_ALLOWED: return dom::MediaKeyStatus::Output_restricted;
+    case KeyStatus::STATUS_INTERNAL_ERROR: return dom::MediaKeyStatus::Internal_error;
+    case KeyStatus::STATUS_PENDING: return dom::MediaKeyStatus::Status_pending;
+    default: return dom::MediaKeyStatus::Internal_error;
+  }
+}
+
+void
+MediaDrmJavaCallbacksSupport::OnSessionBatchedKeyChanged(jni::ByteArray::Param aSessionId,
+                                                         jni::ObjectArray::Param aKeyInfos)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  nsCString sessionId(reinterpret_cast<char*>(aSessionId->GetElements().Elements()),
+                      aSessionId->Length());
+  nsTArray<jni::Object::LocalRef> keyInfosObjectArray(aKeyInfos->GetElements());
+
+  nsTArray<CDMKeyInfo> keyInfosArray;
+
+  for (auto&& keyInfoObject : keyInfosObjectArray) {
+    java::SessionKeyInfo::LocalRef keyInfo(mozilla::Move(keyInfoObject));
+    mozilla::jni::ByteArray::LocalRef keyIdByteArray = keyInfo->KeyId();
+    nsTArray<int8_t> keyIdInt8Array = keyIdByteArray->GetElements();
+    // Cast nsTArray<int8_t> to nsTArray<uint8_t>
+    nsTArray<uint8_t>* keyId = reinterpret_cast<nsTArray<uint8_t>*>(&keyIdInt8Array);
+    auto keyStatus = keyInfo->Status(); // int32_t
+    keyInfosArray.AppendElement(CDMKeyInfo(*keyId,
+                                           dom::Optional<dom::MediaKeyStatus>(
+                                             MediaDrmKeyStatusToMediaKeyStatus(keyStatus)
+                                                                             )
+                                          )
+                               );
+  }
+
+  mDecryptorProxyCallback->BatchedKeyStatusChanged(sessionId,
+                                                   keyInfosArray);
+}
+
+void
+MediaDrmJavaCallbacksSupport::OnRejectPromise(int aPromiseId, jni::String::Param aMessage)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  nsCString reason = aMessage->ToCString();
+  MDRMN_LOG("OnRejectPromise aMessage(%s) ", reason.get());
+  // Current implementation assume all the reject from MediaDrm is due to invalid state.
+  // Other cases should be handled before calling into MediaDrmProxy API.
+  mDecryptorProxyCallback->RejectPromise(aPromiseId,
+                                         NS_ERROR_DOM_INVALID_STATE_ERR,
+                                         reason);
+}
+
+MediaDrmProxySupport::MediaDrmProxySupport(const nsAString& aKeySystem)
+  : mKeySystem(aKeySystem), mDestroyed(false)
+{
+  mJavaCallbacks = MediaDrmProxy::NativeMediaDrmProxyCallbacks::New();
+
+  mBridgeProxy =
+    MediaDrmProxy::Create(mKeySystem,
+                          mJavaCallbacks,
+                          MediaPrefs::PDMAndroidRemoteCodecEnabled());
+}
+
+MediaDrmProxySupport::~MediaDrmProxySupport()
+{
+  MOZ_ASSERT(mDestroyed, "Shutdown() should be called before !!");
+  MediaDrmJavaCallbacksSupport::DisposeNative(mJavaCallbacks);
+}
+
+nsresult
+MediaDrmProxySupport::Init(DecryptorProxyCallback* aCallback)
+{
+  MOZ_ASSERT(mJavaCallbacks);
+
+  mCallback = aCallback;
+  MediaDrmJavaCallbacksSupport::AttachNative(mJavaCallbacks,
+                                             mozilla::MakeUnique<MediaDrmJavaCallbacksSupport>(mCallback));
+  return mBridgeProxy != nullptr ? NS_OK : NS_ERROR_FAILURE;
+}
+
+void
+MediaDrmProxySupport::CreateSession(uint32_t aCreateSessionToken,
+                                    uint32_t aPromiseId,
+                                    const nsCString& aInitDataType,
+                                    const nsTArray<uint8_t>& aInitData,
+                                    MediaDrmSessionType aSessionType)
+{
+  MOZ_ASSERT(mBridgeProxy);
+
+  auto initDataBytes =
+    mozilla::jni::ByteArray::New(reinterpret_cast<const int8_t*>(&aInitData[0]),
+                                 aInitData.Length());
+  // TODO: aSessionType is not used here.
+  // Refer to
+  // http://androidxref.com/5.1.1_r6/xref/external/chromium_org/media/base/android/java/src/org/chromium/media/MediaDrmBridge.java#420
+  // it is hard code to streaming type.
+  mBridgeProxy->CreateSession(aCreateSessionToken,
+                              aPromiseId,
+                              NS_ConvertUTF8toUTF16(aInitDataType),
+                              initDataBytes);
+}
+
+void
+MediaDrmProxySupport::UpdateSession(uint32_t aPromiseId,
+                                    const nsCString& aSessionId,
+                                    const nsTArray<uint8_t>& aResponse)
+{
+  MOZ_ASSERT(mBridgeProxy);
+
+  auto response =
+    mozilla::jni::ByteArray::New(reinterpret_cast<const int8_t*>(aResponse.Elements()),
+                                 aResponse.Length());
+  mBridgeProxy->UpdateSession(aPromiseId,
+                              NS_ConvertUTF8toUTF16(aSessionId),
+                              response);
+}
+
+void
+MediaDrmProxySupport::CloseSession(uint32_t aPromiseId,
+                                   const nsCString& aSessionId)
+{
+  MOZ_ASSERT(mBridgeProxy);
+
+  mBridgeProxy->CloseSession(aPromiseId, NS_ConvertUTF8toUTF16(aSessionId));
+}
+
+void
+MediaDrmProxySupport::Shutdown()
+{
+  MOZ_ASSERT(mBridgeProxy);
+
+  if (mDestroyed) {
+    return;
+  }
+  mBridgeProxy->Destroy();
+  mDestroyed = true;
+}
+
+} // namespace mozilla
\ No newline at end of file
diff --git a/dom/media/eme/mediadrm/MediaDrmProxySupport.h b/dom/media/eme/mediadrm/MediaDrmProxySupport.h
new file mode 100644
index 0000000000..e43b71bc17
--- /dev/null
+++ b/dom/media/eme/mediadrm/MediaDrmProxySupport.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MediaDrmProxySupport_H
+#define MediaDrmProxySupport_H
+
+#include "mozilla/DecryptorProxyCallback.h"
+#include "mozilla/Logging.h"
+#include "FennecJNIWrappers.h"
+#include "nsString.h"
+
+
+namespace mozilla {
+
+enum MediaDrmSessionType {
+  kKeyStreaming = 1,
+  kKeyOffline = 2,
+  kKeyRelease = 3,
+};
+
+#ifndef MDRMN_LOG
+  LogModule* GetMDRMNLog();
+  #define MDRMN_LOG(x, ...) MOZ_LOG(GetMDRMNLog(), mozilla::LogLevel::Debug,\
+    ("[MediaDrmProxySupport][%s]" x, __FUNCTION__, ##__VA_ARGS__))
+#endif
+
+class MediaDrmProxySupport final
+{
+public:
+
+  MediaDrmProxySupport(const nsAString& aKeySystem);
+  ~MediaDrmProxySupport();
+
+  /*
+  * APIs to act as GMPDecryptorAPI, discarding unnecessary calls.
+  */
+  nsresult Init(DecryptorProxyCallback* aCallback);
+
+  void CreateSession(uint32_t aCreateSessionToken,
+                     uint32_t aPromiseId,
+                     const nsCString& aInitDataType,
+                     const nsTArray<uint8_t>& aInitData,
+                     MediaDrmSessionType aSessionType);
+
+  void UpdateSession(uint32_t aPromiseId,
+                     const nsCString& aSessionId,
+                     const nsTArray<uint8_t>& aResponse);
+
+  void CloseSession(uint32_t aPromiseId,
+                    const nsCString& aSessionId);
+
+  void Shutdown();
+
+private:
+  const nsString mKeySystem;
+  java::MediaDrmProxy::GlobalRef mBridgeProxy;
+  java::MediaDrmProxy::NativeMediaDrmProxyCallbacks::GlobalRef mJavaCallbacks;
+  DecryptorProxyCallback* mCallback;
+  bool mDestroyed;
+
+};
+
+} // namespace mozilla
+#endif // MediaDrmProxySupport_H
\ No newline at end of file
diff --git a/dom/media/eme/mediadrm/moz.build b/dom/media/eme/mediadrm/moz.build
new file mode 100644
index 0000000000..c01f7a52e2
--- /dev/null
+++ b/dom/media/eme/mediadrm/moz.build
@@ -0,0 +1,19 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS.mozilla += [
+    'MediaDrmCDMCallbackProxy.h',
+    'MediaDrmCDMProxy.h',
+    'MediaDrmProxySupport.h',
+]
+
+UNIFIED_SOURCES += [
+    'MediaDrmCDMCallbackProxy.cpp',
+    'MediaDrmCDMProxy.cpp',
+    'MediaDrmProxySupport.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
\ No newline at end of file
diff --git a/dom/media/eme/moz.build b/dom/media/eme/moz.build
new file mode 100644
index 0000000000..47e622ae36
--- /dev/null
+++ b/dom/media/eme/moz.build
@@ -0,0 +1,45 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS.mozilla.dom += [
+    'MediaEncryptedEvent.h',
+    'MediaKeyError.h',
+    'MediaKeyMessageEvent.h',
+    'MediaKeys.h',
+    'MediaKeySession.h',
+    'MediaKeyStatusMap.h',
+    'MediaKeySystemAccess.h',
+    'MediaKeySystemAccessManager.h',
+]
+
+EXPORTS.mozilla += [
+    'CDMCaps.h',
+    'CDMProxy.h',
+    'DecryptorProxyCallback.h',
+    'DetailedPromise.h',
+    'EMEUtils.h',
+]
+
+UNIFIED_SOURCES += [
+    'CDMCaps.cpp',
+    'DetailedPromise.cpp',
+    'EMEUtils.cpp',
+    'MediaEncryptedEvent.cpp',
+    'MediaKeyError.cpp',
+    'MediaKeyMessageEvent.cpp',
+    'MediaKeys.cpp',
+    'MediaKeySession.cpp',
+    'MediaKeyStatusMap.cpp',
+    'MediaKeySystemAccess.cpp',
+    'MediaKeySystemAccessManager.cpp',
+]
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
+  DIRS += ['mediadrm']
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+FINAL_LIBRARY = 'xul'