Add m-esr52 at 52.6.0

1 files changed, 835 insertions, 0 deletions

diff --git a/layout/base/nsFrameManager.cpp b/layout/base/nsFrameManager.cpp
new file mode 100644
index 0000000000..97b022da8b
--- /dev/null
+++ b/layout/base/nsFrameManager.cpp
@@ -0,0 +1,835 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim:cindent:ts=2:et:sw=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/.
+ *
+ * This Original Code has been modified by IBM Corporation. Modifications made by IBM 
+ * described herein are Copyright (c) International Business Machines Corporation, 2000.
+ * Modifications to Mozilla code or documentation identified per MPL Section 3.3
+ *
+ * Date             Modified by     Description of modification
+ * 04/20/2000       IBM Corp.      OS/2 VisualAge build.
+ */
+
+/* storage of the frame tree and information about it */
+
+#include "nscore.h"
+#include "nsIPresShell.h"
+#include "nsStyleContext.h"
+#include "nsCOMPtr.h"
+#include "plhash.h"
+#include "nsPlaceholderFrame.h"
+#include "nsGkAtoms.h"
+#include "nsILayoutHistoryState.h"
+#include "nsPresState.h"
+#include "mozilla/dom/Element.h"
+#include "nsIDocument.h"
+
+#include "nsContentUtils.h"
+#include "nsError.h"
+#include "nsAutoPtr.h"
+#include "nsAbsoluteContainingBlock.h"
+#include "ChildIterator.h"
+
+#include "nsFrameManager.h"
+#include "GeckoProfiler.h"
+#include "nsIStatefulFrame.h"
+#include "nsContainerFrame.h"
+
+  #ifdef DEBUG
+    //#define DEBUG_UNDISPLAYED_MAP
+    //#define DEBUG_DISPLAY_CONTENTS_MAP
+  #else
+    #undef DEBUG_UNDISPLAYED_MAP
+    #undef DEBUG_DISPLAY_CONTENTS_MAP
+  #endif
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+//----------------------------------------------------------------------
+
+struct PlaceholderMapEntry : public PLDHashEntryHdr {
+  // key (the out of flow frame) can be obtained through placeholder frame
+  nsPlaceholderFrame *placeholderFrame;
+};
+
+static bool
+PlaceholderMapMatchEntry(const PLDHashEntryHdr *hdr, const void *key)
+{
+  const PlaceholderMapEntry *entry =
+    static_cast<const PlaceholderMapEntry*>(hdr);
+  NS_ASSERTION(entry->placeholderFrame->GetOutOfFlowFrame() !=
+               (void*)0xdddddddd,
+               "Dead placeholder in placeholder map");
+  return entry->placeholderFrame->GetOutOfFlowFrame() == key;
+}
+
+static const PLDHashTableOps PlaceholderMapOps = {
+  PLDHashTable::HashVoidPtrKeyStub,
+  PlaceholderMapMatchEntry,
+  PLDHashTable::MoveEntryStub,
+  PLDHashTable::ClearEntryStub,
+  nullptr
+};
+
+nsFrameManagerBase::nsFrameManagerBase()
+  : mPresShell(nullptr)
+  , mRootFrame(nullptr)
+  , mPlaceholderMap(&PlaceholderMapOps, sizeof(PlaceholderMapEntry))
+  , mUndisplayedMap(nullptr)
+  , mDisplayContentsMap(nullptr)
+  , mIsDestroyingFrames(false)
+{
+}
+
+//----------------------------------------------------------------------
+
+// XXXldb This seems too complicated for what I think it's doing, and it
+// should also be using PLDHashTable rather than plhash to use less memory.
+
+class nsFrameManagerBase::UndisplayedMap {
+public:
+  explicit UndisplayedMap(uint32_t aNumBuckets = 16);
+  ~UndisplayedMap(void);
+
+  UndisplayedNode* GetFirstNode(nsIContent* aParentContent);
+
+  nsresult AddNodeFor(nsIContent* aParentContent,
+                                  nsIContent* aChild, nsStyleContext* aStyle);
+
+  void RemoveNodeFor(nsIContent* aParentContent,
+                                 UndisplayedNode* aNode);
+
+  void RemoveNodesFor(nsIContent* aParentContent);
+  UndisplayedNode* UnlinkNodesFor(nsIContent* aParentContent);
+
+  // Removes all entries from the hash table
+  void  Clear(void);
+
+protected:
+  /**
+   * Gets the entry for the provided parent content. If the content
+   * is a <xbl:children> element, |**aParentContent| is set to
+   * the parent of the children element.
+   */
+  PLHashEntry** GetEntryFor(nsIContent** aParentContent);
+  void          AppendNodeFor(UndisplayedNode* aNode,
+                                          nsIContent* aParentContent);
+
+  PLHashTable*  mTable;
+  PLHashEntry** mLastLookup;
+};
+
+//----------------------------------------------------------------------
+
+nsFrameManager::~nsFrameManager()
+{
+  NS_ASSERTION(!mPresShell, "nsFrameManager::Destroy never called");
+}
+
+void
+nsFrameManager::Destroy()
+{
+  NS_ASSERTION(mPresShell, "Frame manager already shut down.");
+
+  // Destroy the frame hierarchy.
+  mPresShell->SetIgnoreFrameDestruction(true);
+
+  // Unregister all placeholders before tearing down the frame tree
+  nsFrameManager::ClearPlaceholderFrameMap();
+
+  if (mRootFrame) {
+    mRootFrame->Destroy();
+    mRootFrame = nullptr;
+  }
+  
+  delete mUndisplayedMap;
+  mUndisplayedMap = nullptr;
+  delete mDisplayContentsMap;
+  mDisplayContentsMap = nullptr;
+
+  mPresShell = nullptr;
+}
+
+//----------------------------------------------------------------------
+
+// Placeholder frame functions
+nsPlaceholderFrame*
+nsFrameManager::GetPlaceholderFrameFor(const nsIFrame* aFrame)
+{
+  NS_PRECONDITION(aFrame, "null param unexpected");
+
+  auto entry = static_cast<PlaceholderMapEntry*>
+    (const_cast<PLDHashTable*>(&mPlaceholderMap)->Search(aFrame));
+  if (entry) {
+    return entry->placeholderFrame;
+  }
+
+  return nullptr;
+}
+
+void
+nsFrameManager::RegisterPlaceholderFrame(nsPlaceholderFrame* aPlaceholderFrame)
+{
+  MOZ_ASSERT(aPlaceholderFrame, "null param unexpected");
+  MOZ_ASSERT(nsGkAtoms::placeholderFrame == aPlaceholderFrame->GetType(),
+             "unexpected frame type");
+  auto entry = static_cast<PlaceholderMapEntry*>
+    (mPlaceholderMap.Add(aPlaceholderFrame->GetOutOfFlowFrame()));
+  MOZ_ASSERT(!entry->placeholderFrame,
+             "Registering a placeholder for a frame that already has a placeholder!");
+  entry->placeholderFrame = aPlaceholderFrame;
+}
+
+void
+nsFrameManager::UnregisterPlaceholderFrame(nsPlaceholderFrame* aPlaceholderFrame)
+{
+  NS_PRECONDITION(aPlaceholderFrame, "null param unexpected");
+  NS_PRECONDITION(nsGkAtoms::placeholderFrame == aPlaceholderFrame->GetType(),
+                  "unexpected frame type");
+
+  mPlaceholderMap.Remove(aPlaceholderFrame->GetOutOfFlowFrame());
+}
+
+void
+nsFrameManager::ClearPlaceholderFrameMap()
+{
+  for (auto iter = mPlaceholderMap.Iter(); !iter.Done(); iter.Next()) {
+    auto entry = static_cast<PlaceholderMapEntry*>(iter.Get());
+    entry->placeholderFrame->SetOutOfFlowFrame(nullptr);
+  }
+  mPlaceholderMap.Clear();
+}
+
+//----------------------------------------------------------------------
+
+/* static */ nsStyleContext*
+nsFrameManager::GetStyleContextInMap(UndisplayedMap* aMap, nsIContent* aContent)
+{
+  if (!aContent) {
+    return nullptr;
+  }
+  nsIContent* parent = aContent->GetParentElementCrossingShadowRoot();
+  MOZ_ASSERT(parent || !aContent->GetParent(), "no non-elements");
+  for (UndisplayedNode* node = aMap->GetFirstNode(parent);
+         node; node = node->mNext) {
+    if (node->mContent == aContent)
+      return node->mStyle;
+  }
+
+  return nullptr;
+}
+
+/* static */ UndisplayedNode*
+nsFrameManager::GetAllUndisplayedNodesInMapFor(UndisplayedMap* aMap,
+                                               nsIContent* aParentContent)
+{
+  return aMap ? aMap->GetFirstNode(aParentContent) : nullptr;
+}
+
+UndisplayedNode*
+nsFrameManager::GetAllUndisplayedContentIn(nsIContent* aParentContent)
+{
+  return GetAllUndisplayedNodesInMapFor(mUndisplayedMap, aParentContent);
+}
+
+/* static */ void
+nsFrameManager::SetStyleContextInMap(UndisplayedMap* aMap,
+                                     nsIContent* aContent,
+                                     nsStyleContext* aStyleContext)
+{
+  NS_PRECONDITION(!aStyleContext->GetPseudo(),
+                  "Should only have actual elements here");
+
+#if defined(DEBUG_UNDISPLAYED_MAP) || defined(DEBUG_DISPLAY_BOX_CONTENTS_MAP)
+  static int i = 0;
+  printf("SetStyleContextInMap(%d): p=%p \n", i++, (void *)aContent);
+#endif
+
+  NS_ASSERTION(!GetStyleContextInMap(aMap, aContent),
+               "Already have an entry for aContent");
+
+  nsIContent* parent = aContent->GetParentElementCrossingShadowRoot();
+  MOZ_ASSERT(parent || !aContent->GetParent(), "no non-elements");
+#ifdef DEBUG
+  nsIPresShell* shell = aStyleContext->PresContext()->PresShell();
+  NS_ASSERTION(parent || (shell && shell->GetDocument() &&
+                          shell->GetDocument()->GetRootElement() == aContent),
+               "undisplayed content must have a parent, unless it's the root "
+               "element");
+#endif
+  aMap->AddNodeFor(parent, aContent, aStyleContext);
+}
+
+void
+nsFrameManager::SetUndisplayedContent(nsIContent* aContent,
+                                      nsStyleContext* aStyleContext)
+{
+  if (!mUndisplayedMap) {
+    mUndisplayedMap = new UndisplayedMap;
+  }
+  SetStyleContextInMap(mUndisplayedMap, aContent, aStyleContext);
+}
+
+/* static */ void
+nsFrameManager::ChangeStyleContextInMap(UndisplayedMap* aMap,
+                                        nsIContent* aContent,
+                                        nsStyleContext* aStyleContext)
+{
+  MOZ_ASSERT(aMap, "expecting a map");
+
+#if defined(DEBUG_UNDISPLAYED_MAP) || defined(DEBUG_DISPLAY_BOX_CONTENTS_MAP)
+   static int i = 0;
+   printf("ChangeStyleContextInMap(%d): p=%p \n", i++, (void *)aContent);
+#endif
+
+  for (UndisplayedNode* node = aMap->GetFirstNode(aContent->GetParent());
+         node; node = node->mNext) {
+    if (node->mContent == aContent) {
+      node->mStyle = aStyleContext;
+      return;
+    }
+  }
+
+  MOZ_CRASH("couldn't find the entry to change");
+}
+
+void
+nsFrameManager::ClearUndisplayedContentIn(nsIContent* aContent,
+                                          nsIContent* aParentContent)
+{
+#ifdef DEBUG_UNDISPLAYED_MAP
+  static int i = 0;
+  printf("ClearUndisplayedContent(%d): content=%p parent=%p --> ", i++, (void *)aContent, (void*)aParentContent);
+#endif
+  
+  if (mUndisplayedMap) {
+    UndisplayedNode* node = mUndisplayedMap->GetFirstNode(aParentContent);
+    while (node) {
+      if (node->mContent == aContent) {
+        mUndisplayedMap->RemoveNodeFor(aParentContent, node);
+
+#ifdef DEBUG_UNDISPLAYED_MAP
+        printf( "REMOVED!\n");
+#endif
+#ifdef DEBUG
+        // make sure that there are no more entries for the same content
+        nsStyleContext *context = GetUndisplayedContent(aContent);
+        NS_ASSERTION(context == nullptr, "Found more undisplayed content data after removal");
+#endif
+        return;
+      }
+      node = node->mNext;
+    }
+  }
+#ifdef DEBUG_UNDISPLAYED_MAP
+  printf( "not found.\n");
+#endif
+}
+
+void
+nsFrameManager::ClearAllUndisplayedContentIn(nsIContent* aParentContent)
+{
+#ifdef DEBUG_UNDISPLAYED_MAP
+  static int i = 0;
+  printf("ClearAllUndisplayedContentIn(%d): parent=%p \n", i++, (void*)aParentContent);
+#endif
+
+  if (mUndisplayedMap) {
+    mUndisplayedMap->RemoveNodesFor(aParentContent);
+  }
+
+  // Need to look at aParentContent's content list due to XBL insertions.
+  // Nodes in aParentContent's content list do not have aParentContent as a
+  // parent, but are treated as children of aParentContent. We iterate over
+  // the flattened content list and just ignore any nodes we don't care about.
+  FlattenedChildIterator iter(aParentContent);
+  for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
+    if (child->GetParent() != aParentContent) {
+      ClearUndisplayedContentIn(child, child->GetParent());
+    }
+  }
+}
+
+//----------------------------------------------------------------------
+
+void
+nsFrameManager::SetDisplayContents(nsIContent* aContent,
+                                   nsStyleContext* aStyleContext)
+{
+  if (!mDisplayContentsMap) {
+    mDisplayContentsMap = new UndisplayedMap;
+  }
+  SetStyleContextInMap(mDisplayContentsMap, aContent, aStyleContext);
+}
+
+UndisplayedNode*
+nsFrameManager::GetAllDisplayContentsIn(nsIContent* aParentContent)
+{
+  return GetAllUndisplayedNodesInMapFor(mDisplayContentsMap, aParentContent);
+}
+
+void
+nsFrameManager::ClearDisplayContentsIn(nsIContent* aContent,
+                                       nsIContent* aParentContent)
+{
+#ifdef DEBUG_DISPLAY_CONTENTS_MAP
+  static int i = 0;
+  printf("ClearDisplayContents(%d): content=%p parent=%p --> ", i++, (void *)aContent, (void*)aParentContent);
+#endif
+  
+  if (mDisplayContentsMap) {
+    UndisplayedNode* node = mDisplayContentsMap->GetFirstNode(aParentContent);
+    while (node) {
+      if (node->mContent == aContent) {
+        mDisplayContentsMap->RemoveNodeFor(aParentContent, node);
+
+#ifdef DEBUG_DISPLAY_CONTENTS_MAP
+        printf( "REMOVED!\n");
+#endif
+#ifdef DEBUG
+        // make sure that there are no more entries for the same content
+        nsStyleContext* context = GetDisplayContentsStyleFor(aContent);
+        NS_ASSERTION(context == nullptr, "Found more entries for aContent after removal");
+#endif
+        ClearAllDisplayContentsIn(aContent);
+        ClearAllUndisplayedContentIn(aContent);
+        return;
+      }
+      node = node->mNext;
+    }
+  }
+#ifdef DEBUG_DISPLAY_CONTENTS_MAP
+  printf( "not found.\n");
+#endif
+}
+
+void
+nsFrameManager::ClearAllDisplayContentsIn(nsIContent* aParentContent)
+{
+#ifdef DEBUG_DISPLAY_CONTENTS_MAP
+  static int i = 0;
+  printf("ClearAllDisplayContentsIn(%d): parent=%p \n", i++, (void*)aParentContent);
+#endif
+
+  if (mDisplayContentsMap) {
+    UndisplayedNode* cur = mDisplayContentsMap->UnlinkNodesFor(aParentContent);
+    while (cur) {
+      UndisplayedNode* next = cur->mNext;
+      cur->mNext = nullptr;
+      ClearAllDisplayContentsIn(cur->mContent);
+      ClearAllUndisplayedContentIn(cur->mContent);
+      delete cur;
+      cur = next;
+    }
+  }
+
+  // Need to look at aParentContent's content list due to XBL insertions.
+  // Nodes in aParentContent's content list do not have aParentContent as a
+  // parent, but are treated as children of aParentContent. We iterate over
+  // the flattened content list and just ignore any nodes we don't care about.
+  FlattenedChildIterator iter(aParentContent);
+  for (nsIContent* child = iter.GetNextChild(); child; child = iter.GetNextChild()) {
+    if (child->GetParent() != aParentContent) {
+      ClearDisplayContentsIn(child, child->GetParent());
+      ClearUndisplayedContentIn(child, child->GetParent());
+    }
+  }
+}
+
+//----------------------------------------------------------------------
+void
+nsFrameManager::AppendFrames(nsContainerFrame* aParentFrame,
+                             ChildListID       aListID,
+                             nsFrameList&      aFrameList)
+{
+  if (aParentFrame->IsAbsoluteContainer() &&
+      aListID == aParentFrame->GetAbsoluteListID()) {
+    aParentFrame->GetAbsoluteContainingBlock()->
+      AppendFrames(aParentFrame, aListID, aFrameList);
+  } else {
+    aParentFrame->AppendFrames(aListID, aFrameList);
+  }
+}
+
+void
+nsFrameManager::InsertFrames(nsContainerFrame* aParentFrame,
+                             ChildListID       aListID,
+                             nsIFrame*         aPrevFrame,
+                             nsFrameList&      aFrameList)
+{
+  NS_PRECONDITION(!aPrevFrame || (!aPrevFrame->GetNextContinuation()
+                  || (((aPrevFrame->GetNextContinuation()->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER))
+                  && !(aPrevFrame->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER))),
+                  "aPrevFrame must be the last continuation in its chain!");
+
+  if (aParentFrame->IsAbsoluteContainer() &&
+      aListID == aParentFrame->GetAbsoluteListID()) {
+    aParentFrame->GetAbsoluteContainingBlock()->
+      InsertFrames(aParentFrame, aListID, aPrevFrame, aFrameList);
+  } else {
+    aParentFrame->InsertFrames(aListID, aPrevFrame, aFrameList);
+  }
+}
+
+void
+nsFrameManager::RemoveFrame(ChildListID     aListID,
+                            nsIFrame*       aOldFrame)
+{
+  bool wasDestroyingFrames = mIsDestroyingFrames;
+  mIsDestroyingFrames = true;
+
+  // In case the reflow doesn't invalidate anything since it just leaves
+  // a gap where the old frame was, we invalidate it here.  (This is
+  // reasonably likely to happen when removing a last child in a way
+  // that doesn't change the size of the parent.)
+  // This has to sure to invalidate the entire overflow rect; this
+  // is important in the presence of absolute positioning
+  aOldFrame->InvalidateFrameForRemoval();
+
+  NS_ASSERTION(!aOldFrame->GetPrevContinuation() ||
+               // exception for nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames
+               aOldFrame->GetType() == nsGkAtoms::textFrame,
+               "Must remove first continuation.");
+  NS_ASSERTION(!(aOldFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW &&
+                 GetPlaceholderFrameFor(aOldFrame)),
+               "Must call RemoveFrame on placeholder for out-of-flows.");
+  nsContainerFrame* parentFrame = aOldFrame->GetParent();
+  if (parentFrame->IsAbsoluteContainer() &&
+      aListID == parentFrame->GetAbsoluteListID()) {
+    parentFrame->GetAbsoluteContainingBlock()->
+      RemoveFrame(parentFrame, aListID, aOldFrame);
+  } else {
+    parentFrame->RemoveFrame(aListID, aOldFrame);
+  }
+
+  mIsDestroyingFrames = wasDestroyingFrames;
+}
+
+//----------------------------------------------------------------------
+
+void
+nsFrameManager::NotifyDestroyingFrame(nsIFrame* aFrame)
+{
+  nsIContent* content = aFrame->GetContent();
+  if (content && content->GetPrimaryFrame() == aFrame) {
+    ClearAllUndisplayedContentIn(content);
+    ClearAllDisplayContentsIn(content);
+  }
+}
+
+// Capture state for a given frame.
+// Accept a content id here, in some cases we may not have content (scroll position)
+void
+nsFrameManager::CaptureFrameStateFor(nsIFrame* aFrame,
+                                     nsILayoutHistoryState* aState)
+{
+  if (!aFrame || !aState) {
+    NS_WARNING("null frame, or state");
+    return;
+  }
+
+  // Only capture state for stateful frames
+  nsIStatefulFrame* statefulFrame = do_QueryFrame(aFrame);
+  if (!statefulFrame) {
+    return;
+  }
+
+  // Capture the state, exit early if we get null (nothing to save)
+  nsAutoPtr<nsPresState> frameState;
+  nsresult rv = statefulFrame->SaveState(getter_Transfers(frameState));
+  if (!frameState) {
+    return;
+  }
+
+  // Generate the hash key to store the state under
+  // Exit early if we get empty key
+  nsAutoCString stateKey;
+  nsIContent* content = aFrame->GetContent();
+  nsIDocument* doc = content ? content->GetUncomposedDoc() : nullptr;
+  rv = statefulFrame->GenerateStateKey(content, doc, stateKey);
+  if(NS_FAILED(rv) || stateKey.IsEmpty()) {
+    return;
+  }
+
+  // Store the state. aState owns frameState now.
+  aState->AddState(stateKey, frameState.forget());
+}
+
+void
+nsFrameManager::CaptureFrameState(nsIFrame* aFrame,
+                                  nsILayoutHistoryState* aState)
+{
+  NS_PRECONDITION(nullptr != aFrame && nullptr != aState, "null parameters passed in");
+
+  CaptureFrameStateFor(aFrame, aState);
+
+  // Now capture state recursively for the frame hierarchy rooted at aFrame
+  nsIFrame::ChildListIterator lists(aFrame);
+  for (; !lists.IsDone(); lists.Next()) {
+    nsFrameList::Enumerator childFrames(lists.CurrentList());
+    for (; !childFrames.AtEnd(); childFrames.Next()) {
+      nsIFrame* child = childFrames.get();
+      if (child->GetStateBits() & NS_FRAME_OUT_OF_FLOW) {
+        // We'll pick it up when we get to its placeholder
+        continue;
+      }
+      // Make sure to walk through placeholders as needed, so that we
+      // save state for out-of-flows which may not be our descendants
+      // themselves but whose placeholders are our descendants.
+      CaptureFrameState(nsPlaceholderFrame::GetRealFrameFor(child), aState);
+    }
+  }
+}
+
+// Restore state for a given frame.
+// Accept a content id here, in some cases we may not have content (scroll position)
+void
+nsFrameManager::RestoreFrameStateFor(nsIFrame* aFrame,
+                                     nsILayoutHistoryState* aState)
+{
+  if (!aFrame || !aState) {
+    NS_WARNING("null frame or state");
+    return;
+  }
+
+  // Only restore state for stateful frames
+  nsIStatefulFrame* statefulFrame = do_QueryFrame(aFrame);
+  if (!statefulFrame) {
+    return;
+  }
+
+  // Generate the hash key the state was stored under
+  // Exit early if we get empty key
+  nsIContent* content = aFrame->GetContent();
+  // If we don't have content, we can't generate a hash
+  // key and there's probably no state information for us.
+  if (!content) {
+    return;
+  }
+
+  nsAutoCString stateKey;
+  nsIDocument* doc = content->GetUncomposedDoc();
+  nsresult rv = statefulFrame->GenerateStateKey(content, doc, stateKey);
+  if (NS_FAILED(rv) || stateKey.IsEmpty()) {
+    return;
+  }
+
+  // Get the state from the hash
+  nsPresState* frameState = aState->GetState(stateKey);
+  if (!frameState) {
+    return;
+  }
+
+  // Restore it
+  rv = statefulFrame->RestoreState(frameState);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  // If we restore ok, remove the state from the state table
+  aState->RemoveState(stateKey);
+}
+
+void
+nsFrameManager::RestoreFrameState(nsIFrame* aFrame,
+                                  nsILayoutHistoryState* aState)
+{
+  NS_PRECONDITION(nullptr != aFrame && nullptr != aState, "null parameters passed in");
+  
+  RestoreFrameStateFor(aFrame, aState);
+
+  // Now restore state recursively for the frame hierarchy rooted at aFrame
+  nsIFrame::ChildListIterator lists(aFrame);
+  for (; !lists.IsDone(); lists.Next()) {
+    nsFrameList::Enumerator childFrames(lists.CurrentList());
+    for (; !childFrames.AtEnd(); childFrames.Next()) {
+      RestoreFrameState(childFrames.get(), aState);
+    }
+  }
+}
+
+//----------------------------------------------------------------------
+
+static PLHashNumber
+HashKey(void* key)
+{
+  return NS_PTR_TO_INT32(key);
+}
+
+static int
+CompareKeys(void* key1, void* key2)
+{
+  return key1 == key2;
+}
+
+//----------------------------------------------------------------------
+
+nsFrameManagerBase::UndisplayedMap::UndisplayedMap(uint32_t aNumBuckets)
+{
+  MOZ_COUNT_CTOR(nsFrameManagerBase::UndisplayedMap);
+  mTable = PL_NewHashTable(aNumBuckets, (PLHashFunction)HashKey,
+                           (PLHashComparator)CompareKeys,
+                           (PLHashComparator)nullptr,
+                           nullptr, nullptr);
+  mLastLookup = nullptr;
+}
+
+nsFrameManagerBase::UndisplayedMap::~UndisplayedMap(void)
+{
+  MOZ_COUNT_DTOR(nsFrameManagerBase::UndisplayedMap);
+  Clear();
+  PL_HashTableDestroy(mTable);
+}
+
+PLHashEntry**  
+nsFrameManagerBase::UndisplayedMap::GetEntryFor(nsIContent** aParentContent)
+{
+  nsIContent* parentContent = *aParentContent;
+
+  if (mLastLookup && (parentContent == (*mLastLookup)->key)) {
+    return mLastLookup;
+  }
+
+  // In the case of XBL default content, <xbl:children> elements do not get a
+  // frame causing a mismatch between the content tree and the frame tree.
+  // |GetEntryFor| is sometimes called with the content tree parent (which may
+  // be a <xbl:children> element) but the parent in the frame tree would be the
+  // insertion parent (parent of the <xbl:children> element). Here the children
+  // elements are normalized to the insertion parent to correct for the mismatch.
+  if (parentContent && nsContentUtils::IsContentInsertionPoint(parentContent)) {
+    parentContent = parentContent->GetParent();
+    // Change the caller's pointer for the parent content to be the insertion parent.
+    *aParentContent = parentContent;
+  }
+
+  PLHashNumber hashCode = NS_PTR_TO_INT32(parentContent);
+  PLHashEntry** entry = PL_HashTableRawLookup(mTable, hashCode, parentContent);
+  if (*entry) {
+    mLastLookup = entry;
+  }
+  return entry;
+}
+
+UndisplayedNode* 
+nsFrameManagerBase::UndisplayedMap::GetFirstNode(nsIContent* aParentContent)
+{
+  PLHashEntry** entry = GetEntryFor(&aParentContent);
+  if (*entry) {
+    return (UndisplayedNode*)((*entry)->value);
+  }
+  return nullptr;
+}
+
+void
+nsFrameManagerBase::UndisplayedMap::AppendNodeFor(UndisplayedNode* aNode,
+                                                  nsIContent* aParentContent)
+{
+  PLHashEntry** entry = GetEntryFor(&aParentContent);
+  if (*entry) {
+    UndisplayedNode*  node = (UndisplayedNode*)((*entry)->value);
+    while (node->mNext) {
+      if (node->mContent == aNode->mContent) {
+        // We actually need to check this in optimized builds because
+        // there are some callers that do this.  See bug 118014, bug
+        // 136704, etc.
+        NS_NOTREACHED("node in map twice");
+        delete aNode;
+        return;
+      }
+      node = node->mNext;
+    }
+    node->mNext = aNode;
+  }
+  else {
+    PLHashNumber hashCode = NS_PTR_TO_INT32(aParentContent);
+    PL_HashTableRawAdd(mTable, entry, hashCode, aParentContent, aNode);
+    mLastLookup = nullptr; // hashtable may have shifted bucket out from under us
+  }
+}
+
+nsresult 
+nsFrameManagerBase::UndisplayedMap::AddNodeFor(nsIContent* aParentContent,
+                                               nsIContent* aChild, 
+                                               nsStyleContext* aStyle)
+{
+  UndisplayedNode*  node = new UndisplayedNode(aChild, aStyle);
+
+  AppendNodeFor(node, aParentContent);
+  return NS_OK;
+}
+
+void
+nsFrameManagerBase::UndisplayedMap::RemoveNodeFor(nsIContent* aParentContent,
+                                                  UndisplayedNode* aNode)
+{
+  PLHashEntry** entry = GetEntryFor(&aParentContent);
+  NS_ASSERTION(*entry, "content not in map");
+  if (*entry) {
+    if ((UndisplayedNode*)((*entry)->value) == aNode) {  // first node
+      if (aNode->mNext) {
+        (*entry)->value = aNode->mNext;
+        aNode->mNext = nullptr;
+      }
+      else {
+        PL_HashTableRawRemove(mTable, entry, *entry);
+        mLastLookup = nullptr; // hashtable may have shifted bucket out from under us
+      }
+    }
+    else {
+      UndisplayedNode*  node = (UndisplayedNode*)((*entry)->value);
+      while (node->mNext) {
+        if (node->mNext == aNode) {
+          node->mNext = aNode->mNext;
+          aNode->mNext = nullptr;
+          break;
+        }
+        node = node->mNext;
+      }
+    }
+  }
+  delete aNode;
+}
+
+
+UndisplayedNode*
+nsFrameManagerBase::UndisplayedMap::UnlinkNodesFor(nsIContent* aParentContent)
+{
+  PLHashEntry** entry = GetEntryFor(&aParentContent);
+  NS_ASSERTION(entry, "content not in map");
+  if (*entry) {
+    UndisplayedNode* node = (UndisplayedNode*)((*entry)->value);
+    NS_ASSERTION(node, "null node for non-null entry in UndisplayedMap");
+    PL_HashTableRawRemove(mTable, entry, *entry);
+    mLastLookup = nullptr; // hashtable may have shifted bucket out from under us
+    return node;
+  }
+  return nullptr;
+}
+
+void
+nsFrameManagerBase::UndisplayedMap::RemoveNodesFor(nsIContent* aParentContent)
+{
+  delete UnlinkNodesFor(aParentContent);
+}
+
+static int
+RemoveUndisplayedEntry(PLHashEntry* he, int i, void* arg)
+{
+  UndisplayedNode*  node = (UndisplayedNode*)(he->value);
+  delete node;
+  // Remove and free this entry and continue enumerating
+  return HT_ENUMERATE_REMOVE | HT_ENUMERATE_NEXT;
+}
+
+void
+nsFrameManagerBase::UndisplayedMap::Clear(void)
+{
+  mLastLookup = nullptr;
+  PL_HashTableEnumerateEntries(mTable, RemoveUndisplayedEntry, 0);
+}
+
+uint32_t nsFrameManagerBase::sGlobalGenerationNumber;