Issue #1829 - Revert “Issue #1751 -- Remove XP_MACOSX conditionals from the rest of the tree.”

This also removes some PP abuse and takes file entries out of PP when no longer
needed without XP_MACOSX conditionals.

This reverts commit 6f707bde95dab6998ac204f9ee6c925ee230c740.

71 files changed, 1800 insertions, 99 deletions

diff --git a/toolkit/components/apppicker/content/appPicker.js b/toolkit/components/apppicker/content/appPicker.js
index 6922fce39f..21a007632b 100644
--- a/toolkit/components/apppicker/content/appPicker.js
+++ b/toolkit/components/apppicker/content/appPicker.js
@@ -119,6 +119,12 @@ AppPicker.prototype =
           return file.getVersionInfoField("FileDescription");
         } catch (e) {}
       }
+#elifdef XP_MACOSX
+      if (file instanceof Components.interfaces.nsILocalFileMac) {
+        try {
+          return file.bundleDisplayName;
+        } catch (e) {}
+      }
 #endif
       return file.leafName;
     },
@@ -177,6 +183,8 @@ AppPicker.prototype =
       var startLocation;
 #ifdef XP_WIN
       startLocation = "ProgF"; // Program Files
+#elifdef XP_MACOSX
+      startLocation = "LocApp"; // Local Applications
 #else
       startLocation = "Home";
 #endif
diff --git a/toolkit/components/blocklist/nsBlocklistService.js b/toolkit/components/blocklist/nsBlocklistService.js
index 188fdfb387..f016fe6cdc 100644
--- a/toolkit/components/blocklist/nsBlocklistService.js
+++ b/toolkit/components/blocklist/nsBlocklistService.js
@@ -114,6 +114,15 @@ XPCOMUtils.defineLazyGetter(this, "gABI", function() {
     LOG("BlockList Global gABI: XPCOM ABI unknown.");
   }
 
+#ifdef XP_MACOSX
+  // Mac universal build should report a different ABI than either macppc
+  // or mactel.
+  let macutils = Cc["@mozilla.org/xpcom/mac-utils;1"].
+                 getService(Ci.nsIMacUtils);
+
+  if (macutils.isUniversalBinary)
+    abi += "-u-" + macutils.architecturesInBinary;
+#endif
   return abi;
 });
 
diff --git a/toolkit/components/downloads/nsDownloadManager.cpp b/toolkit/components/downloads/nsDownloadManager.cpp
index bc01b9ae58..587c1ac8ab 100644
--- a/toolkit/components/downloads/nsDownloadManager.cpp
+++ b/toolkit/components/downloads/nsDownloadManager.cpp
@@ -57,6 +57,10 @@
 #endif
 #endif
 
+#ifdef XP_MACOSX
+#include <CoreFoundation/CoreFoundation.h>
+#endif
+
 #ifdef MOZ_WIDGET_GTK
 #include <gtk/gtk.h>
 #endif
@@ -1372,7 +1376,12 @@ nsDownloadManager::GetDefaultDownloadsDirectory(nsIFile **aResult)
   mBundle->GetStringFromName(u"downloadsFolder",
                              getter_Copies(folderName));
 
-#if defined(XP_WIN)
+#if defined (XP_MACOSX)
+  rv = dirService->Get(NS_OSX_DEFAULT_DOWNLOAD_DIR,
+                       NS_GET_IID(nsIFile),
+                       getter_AddRefs(downloadDir));
+  NS_ENSURE_SUCCESS(rv, rv);
+#elif defined(XP_WIN)
   rv = dirService->Get(NS_WIN_DEFAULT_DOWNLOAD_DIR,
                        NS_GET_IID(nsIFile),
                        getter_AddRefs(downloadDir));
@@ -2436,11 +2445,19 @@ nsDownloadManager::Observe(nsISupports *aSubject,
     nsCOMPtr<nsISupportsPRBool> cancelDownloads =
       do_QueryInterface(aSubject, &rv);
     NS_ENSURE_SUCCESS(rv, rv);
+#ifndef XP_MACOSX
     ConfirmCancelDownloads(currDownloadCount, cancelDownloads,
                            u"quitCancelDownloadsAlertTitle",
                            u"quitCancelDownloadsAlertMsgMultiple",
                            u"quitCancelDownloadsAlertMsg",
                            u"dontQuitButtonWin");
+#else
+    ConfirmCancelDownloads(currDownloadCount, cancelDownloads,
+                           u"quitCancelDownloadsAlertTitle",
+                           u"quitCancelDownloadsAlertMsgMacMultiple",
+                           u"quitCancelDownloadsAlertMsgMac",
+                           u"dontQuitButtonMac");
+#endif
   } else if (strcmp(aTopic, "offline-requested") == 0 && currDownloadCount) {
     nsCOMPtr<nsISupportsPRBool> cancelDownloads =
       do_QueryInterface(aSubject, &rv);
@@ -2730,7 +2747,7 @@ nsDownload::SetState(DownloadState aState)
         }
       }
 
-#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+#if defined(XP_WIN) || defined(XP_MACOSX) || defined(MOZ_WIDGET_GTK)
       nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(mTarget);
       nsCOMPtr<nsIFile> file;
       nsAutoString path;
@@ -2740,6 +2757,7 @@ nsDownload::SetState(DownloadState aState)
           file &&
           NS_SUCCEEDED(file->GetPath(path))) {
 
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
         // On Windows and Gtk, add the download to the system's "recent documents"
         // list, with a pref to disable.
         {
@@ -2777,6 +2795,18 @@ nsDownload::SetState(DownloadState aState)
           g_object_unref(gio_file);
 #endif
         }
+#endif
+
+#ifdef XP_MACOSX
+        // On OS X, make the downloads stack bounce.
+        CFStringRef observedObject = ::CFStringCreateWithCString(kCFAllocatorDefault,
+                                                 NS_ConvertUTF16toUTF8(path).get(),
+                                                 kCFStringEncodingUTF8);
+        CFNotificationCenterRef center = ::CFNotificationCenterGetDistributedCenter();
+        ::CFNotificationCenterPostNotification(center, CFSTR("com.apple.DownloadFileFinished"),
+                                               observedObject, nullptr, TRUE);
+        ::CFRelease(observedObject);
+#endif
       }
 
 #ifdef XP_WIN
@@ -3359,10 +3389,14 @@ nsDownload::OpenWithApplication()
   if (!prefs || NS_FAILED(prefs->GetBoolPref(PREF_BH_DELETETEMPFILEONEXIT,
                                              &deleteTempFileOnExit))) {
     // No prefservice or no pref set; use default value
-    // Some users have been very verbal about temp files being deleted on
+#if !defined(XP_MACOSX)
+    // Mac users have been very verbal about temp files being deleted on
     // app exit - they don't like it - but we'll continue to do this on
-    // all platforms for now.
+    // other platforms for now.
     deleteTempFileOnExit = true;
+#else
+    deleteTempFileOnExit = false;
+#endif
   }
 
   // Always schedule files to be deleted at the end of the private browsing
diff --git a/toolkit/components/jsdownloads/src/DownloadIntegration.jsm b/toolkit/components/jsdownloads/src/DownloadIntegration.jsm
index 8b5c644987..22a6570dac 100644
--- a/toolkit/components/jsdownloads/src/DownloadIntegration.jsm
+++ b/toolkit/components/jsdownloads/src/DownloadIntegration.jsm
@@ -294,7 +294,9 @@ this.DownloadIntegration = {
     }
 
     let directoryPath = null;
-#ifdef XP_WIN
+#ifdef XP_MACOSX
+    directoryPath = this._getDirectory("DfltDwnld");
+#elifdef XP_WIN
     // For XP/2K, use My Documents/Downloads. Other version uses
     // the default Downloads directory.
     let version = parseFloat(Services.sysinfo.getProperty("version"));
@@ -363,7 +365,11 @@ this.DownloadIntegration = {
    */
   getTemporaryDownloadsDirectory: Task.async(function* () {
     let directoryPath = null;
+#ifdef XP_MACOSX
+    directoryPath = yield this.getPreferredDownloadsDirectory();
+#else
     directoryPath = this._getDirectory("TmpD");
+#endif
     return directoryPath;
   }),
 
diff --git a/toolkit/components/jsdownloads/src/DownloadPlatform.cpp b/toolkit/components/jsdownloads/src/DownloadPlatform.cpp
index 14277e5bd4..66ad2b8fa8 100644
--- a/toolkit/components/jsdownloads/src/DownloadPlatform.cpp
+++ b/toolkit/components/jsdownloads/src/DownloadPlatform.cpp
@@ -25,6 +25,11 @@
 #include "nsILocalFileWin.h"
 #endif
 
+#ifdef XP_MACOSX
+#include <CoreFoundation/CoreFoundation.h>
+#include "../../../../xpcom/io/CocoaFileUtils.h"
+#endif
+
 #ifdef MOZ_WIDGET_GTK
 #include <gtk/gtk.h>
 #endif
@@ -64,13 +69,39 @@ static void gio_set_metadata_done(GObject *source_obj, GAsyncResult *res, gpoint
 }
 #endif
 
+#ifdef XP_MACOSX
+// Caller is responsible for freeing any result (CF Create Rule)
+CFURLRef CreateCFURLFromNSIURI(nsIURI *aURI) {
+  nsAutoCString spec;
+  if (aURI) {
+    aURI->GetSpec(spec);
+  }
+
+  CFStringRef urlStr = ::CFStringCreateWithCString(kCFAllocatorDefault,
+                                                   spec.get(),
+                                                   kCFStringEncodingUTF8);
+  if (!urlStr) {
+    return NULL;
+  }
+
+  CFURLRef url = ::CFURLCreateWithString(kCFAllocatorDefault,
+                                         urlStr,
+                                         NULL);
+
+  ::CFRelease(urlStr);
+
+  return url;
+}
+#endif
+
 nsresult DownloadPlatform::DownloadDone(nsIURI* aSource, nsIURI* aReferrer, nsIFile* aTarget,
                                         const nsACString& aContentType, bool aIsPrivate)
 {
-#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+#if defined(XP_WIN) || defined(XP_MACOSX) || defined(MOZ_WIDGET_GTK)
 
   nsAutoString path;
   if (aTarget && NS_SUCCEEDED(aTarget->GetPath(path))) {
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
     // On Windows and Gtk, add the download to the system's "recent documents"
     // list, with a pref to disable.
     {
@@ -105,10 +136,53 @@ nsresult DownloadPlatform::DownloadDone(nsIURI* aSource, nsIURI* aReferrer, nsIF
                                   nullptr, gio_set_metadata_done, nullptr);
       g_object_unref(file_info);
       g_object_unref(gio_file);
-#endif // MOZ_ENABLE_GIO
+#endif
     }
+#endif
+
+#ifdef XP_MACOSX
+    // On OS X, make the downloads stack bounce.
+    CFStringRef observedObject = ::CFStringCreateWithCString(kCFAllocatorDefault,
+                                             NS_ConvertUTF16toUTF8(path).get(),
+                                             kCFStringEncodingUTF8);
+    CFNotificationCenterRef center = ::CFNotificationCenterGetDistributedCenter();
+    ::CFNotificationCenterPostNotification(center, CFSTR("com.apple.DownloadFileFinished"),
+                                           observedObject, nullptr, TRUE);
+    ::CFRelease(observedObject);
+
+    // Add OS X origin and referrer file metadata
+    CFStringRef pathCFStr = NULL;
+    if (!path.IsEmpty()) {
+      pathCFStr = ::CFStringCreateWithCharacters(kCFAllocatorDefault,
+                                                 (const UniChar*)path.get(),
+                                                 path.Length());
+    }
+    if (pathCFStr) {
+      bool isFromWeb = IsURLPossiblyFromWeb(aSource);
+
+      CFURLRef sourceCFURL = CreateCFURLFromNSIURI(aSource);
+      CFURLRef referrerCFURL = CreateCFURLFromNSIURI(aReferrer);
+
+      CocoaFileUtils::AddOriginMetadataToFile(pathCFStr,
+                                              sourceCFURL,
+                                              referrerCFURL);
+      CocoaFileUtils::AddQuarantineMetadataToFile(pathCFStr,
+                                                  sourceCFURL,
+                                                  referrerCFURL,
+                                                  isFromWeb);
+
+      ::CFRelease(pathCFStr);
+      if (sourceCFURL) {
+        ::CFRelease(sourceCFURL);
+      }
+      if (referrerCFURL) {
+        ::CFRelease(referrerCFURL);
+      }
+    }
+#endif
   }
-#endif // defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+
+#endif
 
   return NS_OK;
 }
diff --git a/toolkit/components/jsdownloads/src/DownloadUIHelper.jsm b/toolkit/components/jsdownloads/src/DownloadUIHelper.jsm
index 860a325d4b..3039525f5f 100644
--- a/toolkit/components/jsdownloads/src/DownloadUIHelper.jsm
+++ b/toolkit/components/jsdownloads/src/DownloadUIHelper.jsm
@@ -184,10 +184,17 @@ this.DownloadPrompter.prototype = {
     switch (aPromptType) {
       case this.ON_QUIT:
         title = s.quitCancelDownloadsAlertTitle;
+#ifdef XP_MACOSX
+        message = aDownloadsCount > 1
+                  ? s.quitCancelDownloadsAlertMsgMacMultiple(aDownloadsCount)
+                  : s.quitCancelDownloadsAlertMsgMac;
+        cancelButton = s.dontQuitButtonMac;
+#else
         message = aDownloadsCount > 1
                   ? s.quitCancelDownloadsAlertMsgMultiple(aDownloadsCount)
                   : s.quitCancelDownloadsAlertMsg;
         cancelButton = s.dontQuitButtonWin;
+#endif
         break;
       case this.ON_OFFLINE:
         title = s.offlineCancelDownloadsAlertTitle;
diff --git a/toolkit/components/jsdownloads/src/moz.build b/toolkit/components/jsdownloads/src/moz.build
index 115435f641..5a08340ae2 100644
--- a/toolkit/components/jsdownloads/src/moz.build
+++ b/toolkit/components/jsdownloads/src/moz.build
@@ -18,11 +18,11 @@ EXTRA_JS_MODULES += [
     'DownloadList.jsm',
     'Downloads.jsm',
     'DownloadStore.jsm',
-    'DownloadUIHelper.jsm',
 ]
 
 EXTRA_PP_JS_MODULES += [
     'DownloadIntegration.jsm',
+    'DownloadUIHelper.jsm',
 ]
 
 FINAL_LIBRARY = 'xul'
diff --git a/toolkit/components/passwordmgr/content/passwordManager.js b/toolkit/components/passwordmgr/content/passwordManager.js
index 4db3e81b9a..2d71d05f64 100644
--- a/toolkit/components/passwordmgr/content/passwordManager.js
+++ b/toolkit/components/passwordmgr/content/passwordManager.js
@@ -479,7 +479,12 @@ function HandleSignonKeyPress(e) {
     return;
   }
 
+#ifdef XP_MACOSX
+  if (e.keyCode == KeyboardEvent.DOM_VK_DELETE ||
+      e.keyCode == KeyboardEvent.DOM_VK_BACK_SPACE) {
+#else
   if (e.keyCode == KeyboardEvent.DOM_VK_DELETE) {
+#endif
     DeleteSignon();
   }
 }
diff --git a/toolkit/components/passwordmgr/content/passwordManager.xul b/toolkit/components/passwordmgr/content/passwordManager.xul
index b2713ae6c7..8590d96aca 100644
--- a/toolkit/components/passwordmgr/content/passwordManager.xul
+++ b/toolkit/components/passwordmgr/content/passwordManager.xul
@@ -1,4 +1,4 @@
-<?xml version="1.0"?> <!-- -*- Mode: XML; indent-tabs-mode: nil -*- -->
+<?xml version="1.0"?> <!-- -*- Mode: SGML; indent-tabs-mode: nil -*- -->
 # 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/.
@@ -126,8 +126,10 @@
   <hbox align="end">
     <hbox class="actionButtons" flex="1">
       <spacer flex="1"/>
+#ifndef XP_MACOSX
       <button oncommand="close();" icon="close"
               label="&closebutton.label;" accesskey="&closebutton.accesskey;"/>
+#endif
     </hbox>
   </hbox>
 </window>
diff --git a/toolkit/components/perfmonitoring/nsPerformanceStats.cpp b/toolkit/components/perfmonitoring/nsPerformanceStats.cpp
index 15a021bbab..59d84ced15 100644
--- a/toolkit/components/perfmonitoring/nsPerformanceStats.cpp
+++ b/toolkit/components/perfmonitoring/nsPerformanceStats.cpp
@@ -35,7 +35,14 @@
 #include <unistd.h>
 #endif // defined(XP_WIN)
 
-#if defined(XP_UNIX)
+#if defined(XP_MACOSX)
+#include <mach/mach_init.h>
+#include <mach/mach_interface.h>
+#include <mach/mach_port.h>
+#include <mach/mach_types.h>
+#include <mach/message.h>
+#include <mach/thread_info.h>
+#elif defined(XP_UNIX)
 #include <sys/time.h>
 #include <sys/resource.h>
 #endif // defined(XP_UNIX)
@@ -1232,7 +1239,30 @@ nsPerformanceStatsService::GetResources(uint64_t* userTime,
   MOZ_ASSERT(userTime);
   MOZ_ASSERT(systemTime);
 
-#if defined(XP_UNIX)
+#if defined(XP_MACOSX)
+  // On MacOS X, to get we per-thread data, we need to
+  // reach into the kernel.
+
+  mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
+  thread_basic_info_data_t info;
+  mach_port_t port = mach_thread_self();
+  kern_return_t err =
+    thread_info(/* [in] targeted thread*/ port,
+                /* [in] nature of information*/ THREAD_BASIC_INFO,
+                /* [out] thread information */  (thread_info_t)&info,
+                /* [inout] number of items */   &count);
+
+  // We do not need ability to communicate with the thread, so
+  // let's release the port.
+  mach_port_deallocate(mach_task_self(), port);
+
+  if (err != KERN_SUCCESS)
+    return NS_ERROR_FAILURE;
+
+  *userTime = info.user_time.microseconds + info.user_time.seconds * 1000000;
+  *systemTime = info.system_time.microseconds + info.system_time.seconds * 1000000;
+
+#elif defined(XP_UNIX)
   struct rusage rusage;
 #if defined(RUSAGE_THREAD)
   // Under Linux, we can obtain per-thread statistics
@@ -1276,7 +1306,7 @@ nsPerformanceStatsService::GetResources(uint64_t* userTime,
   // Convert 100 ns to 1 us.
   *userTime = userTimeInt.QuadPart / 10;
 
-#endif // defined(XP_UNIX) || defined(XP_WIN)
+#endif // defined(XP_MACOSX) || defined(XP_UNIX) || defined(XP_WIN)
 
   return NS_OK;
 }
diff --git a/toolkit/components/places/PlacesUtils.jsm b/toolkit/components/places/PlacesUtils.jsm
index ab753ba86b..259fb7aa7d 100644
--- a/toolkit/components/places/PlacesUtils.jsm
+++ b/toolkit/components/places/PlacesUtils.jsm
@@ -60,8 +60,14 @@ XPCOMUtils.defineLazyModuleGetter(this, "PlacesUIUtils",
 // refresh instead.
 const MIN_TRANSACTIONS_FOR_BATCH = 5;
 
-// The transferable system converts "\r\n" to "\n" where needed.
+// On Mac OSX, the transferable system converts "\r\n" to "\n\n", where
+// we really just want "\n". On other platforms, the transferable system
+// converts "\r\n" to "\n".
+#ifdef XP_MACOSX
+const NEWLINE = "\n";
+#else
 const NEWLINE = "\r\n";
+#endif
 
 function QI_node(aNode, aIID) {
   var result = null;
diff --git a/toolkit/components/places/moz.build b/toolkit/components/places/moz.build
index 4c6ce89565..fda73f761f 100644
--- a/toolkit/components/places/moz.build
+++ b/toolkit/components/places/moz.build
@@ -68,9 +68,10 @@ if CONFIG['MOZ_PLACES']:
         'PlacesSearchAutocompleteProvider.jsm',
         'PlacesSyncUtils.jsm',
         'PlacesTransactions.jsm',
-        'PlacesUtils.jsm',
     ]
 
+    EXTRA_PP_JS_MODULES += ['PlacesUtils.jsm']
+
     EXTRA_COMPONENTS += [
         'ColorAnalyzer.js',
         'nsLivemarkService.js',
diff --git a/toolkit/components/printing/jar.mn b/toolkit/components/printing/jar.mn
index f77cf1c6aa..a0e9510304 100644
--- a/toolkit/components/printing/jar.mn
+++ b/toolkit/components/printing/jar.mn
@@ -6,9 +6,11 @@ toolkit.jar:
    content/global/printdialog.js                    (content/printdialog.js)
    content/global/printdialog.xul                   (content/printdialog.xul)
 #ifdef XP_UNIX
+#ifndef XP_MACOSX
    content/global/printjoboptions.js                (content/printjoboptions.js)
    content/global/printjoboptions.xul               (content/printjoboptions.xul)
 #endif
+#endif
    content/global/printPageSetup.js                 (content/printPageSetup.js)
    content/global/printPageSetup.xul                (content/printPageSetup.xul)
 *  content/global/printPreviewBindings.xml          (content/printPreviewBindings.xml)
diff --git a/toolkit/components/prompts/content/commonDialog.xul b/toolkit/components/prompts/content/commonDialog.xul
index a7621ccdfb..990b26586b 100644
--- a/toolkit/components/prompts/content/commonDialog.xul
+++ b/toolkit/components/prompts/content/commonDialog.xul
@@ -3,6 +3,7 @@
    - 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/. -->
 
+
 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://global/content/commonDialog.css" type="text/css"?>
 <?xml-stylesheet href="chrome://global/skin/commonDialog.css" type="text/css"?>
@@ -62,9 +63,18 @@
         <hbox id="iconContainer" align="start">
           <image id="info.icon" class="spaced"/>
         </hbox>
-        <vbox id="infoContainer" pack="center">
+        <vbox id="infoContainer"
+#ifndef XP_MACOSX
+              pack="center"
+#endif
+        >
+          <!-- Only shown on OS X, since it has no dialog title -->
           <description id="info.title"
+#ifndef XP_MACOSX
             hidden="true"
+#else
+            style="margin-bottom: 1em"
+#endif
           />
           <description id="info.body" context="contentAreaContextMenu" noinitialfocus="true"/>
         </vbox>
diff --git a/toolkit/components/prompts/content/tabprompts.xml b/toolkit/components/prompts/content/tabprompts.xml
index 5355bb4cff..0ce13203c1 100644
--- a/toolkit/components/prompts/content/tabprompts.xml
+++ b/toolkit/components/prompts/content/tabprompts.xml
@@ -315,16 +315,27 @@
                  group="system" action="this.onKeyAction('default', event);"/>
         <handler event="keypress" keycode="VK_ESCAPE"
                  group="system" action="this.onKeyAction('cancel', event);"/>
+#ifdef XP_MACOSX
+        <handler event="keypress" key="." modifiers="meta"
+                 group="system" action="this.onKeyAction('cancel', event);"/>
+#endif
         <handler event="focus" phase="capturing">
             let bnum = this.args.defaultButtonNum || 0;
             let defaultButton = this.ui["button" + bnum];
 
-            // The default button is only marked as such when no other button has focus.
-            // XUL buttons will react to pressing enter as a command, so you can't trigger
-            // the default without tabbing to it or something that isn't a button.
+#ifdef XP_MACOSX
+            // On OS X, the default button always stays marked as such (until
+            // the entire prompt blurs).
+            defaultButton.setAttribute("default", true);
+#else
+            // On other platforms, the default button is only marked as such
+            // when no other button has focus. XUL buttons on not-OSX will
+            // react to pressing enter as a command, so you can't trigger the
+            // default without tabbing to it or something that isn't a button.
             let focusedDefault = (event.originalTarget == defaultButton);
             let someButtonFocused = event.originalTarget instanceof Ci.nsIDOMXULButtonElement;
             defaultButton.setAttribute("default", focusedDefault || !someButtonFocused);
+#endif
         </handler>
         <handler event="blur">
             // If focus shifted to somewhere else in the browser, don't make
diff --git a/toolkit/components/prompts/jar.mn b/toolkit/components/prompts/jar.mn
index 1b5da3f801..60ecbdcbc4 100644
--- a/toolkit/components/prompts/jar.mn
+++ b/toolkit/components/prompts/jar.mn
@@ -4,7 +4,7 @@
 
 toolkit.jar:
    content/global/commonDialog.js             (content/commonDialog.js)
-   content/global/commonDialog.xul            (content/commonDialog.xul)
+*  content/global/commonDialog.xul            (content/commonDialog.xul)
    content/global/commonDialog.css            (content/commonDialog.css)
    content/global/selectDialog.js             (content/selectDialog.js)
    content/global/selectDialog.xul            (content/selectDialog.xul)
diff --git a/toolkit/components/satchel/nsFormFillController.cpp b/toolkit/components/satchel/nsFormFillController.cpp
index 880ca79b21..bebc60f521 100644
--- a/toolkit/components/satchel/nsFormFillController.cpp
+++ b/toolkit/components/satchel/nsFormFillController.cpp
@@ -1016,11 +1016,27 @@ nsFormFillController::KeyPress(nsIDOMEvent* aEvent)
   keyEvent->GetKeyCode(&k);
   switch (k) {
   case nsIDOMKeyEvent::DOM_VK_DELETE:
+#ifndef XP_MACOSX
     mController->HandleDelete(&cancel);
     break;
   case nsIDOMKeyEvent::DOM_VK_BACK_SPACE:
     mController->HandleText(&unused);
     break;
+#else
+  case nsIDOMKeyEvent::DOM_VK_BACK_SPACE:
+    {
+      bool isShift = false;
+      keyEvent->GetShiftKey(&isShift);
+
+      if (isShift) {
+        mController->HandleDelete(&cancel);
+      } else {
+        mController->HandleText(&unused);
+      }
+
+      break;
+    }
+#endif
   case nsIDOMKeyEvent::DOM_VK_PAGE_UP:
   case nsIDOMKeyEvent::DOM_VK_PAGE_DOWN:
     {
diff --git a/toolkit/components/startup/nsAppStartup.cpp b/toolkit/components/startup/nsAppStartup.cpp
index 11a000270e..7f67323b7d 100644
--- a/toolkit/components/startup/nsAppStartup.cpp
+++ b/toolkit/components/startup/nsAppStartup.cpp
@@ -273,6 +273,10 @@ nsAppStartup::Run(void)
   // with a zombie process.
 
   if (!mShuttingDown && mConsiderQuitStopper != 0) {
+#ifdef XP_MACOSX
+    EnterLastWindowClosingSurvivalArea();
+#endif
+
     mRunning = true;
 
     nsresult rv = mAppShell->Run();
@@ -308,10 +312,45 @@ nsAppStartup::Quit(uint32_t aMode)
 
   // If we're considering quitting, we will only do so if:
   if (ferocity == eConsiderQuit) {
+#ifdef XP_MACOSX
+    nsCOMPtr<nsIAppShellService> appShell
+      (do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
+    bool hasHiddenPrivateWindow = false;
+    if (appShell) {
+      appShell->GetHasHiddenPrivateWindow(&hasHiddenPrivateWindow);
+    }
+    int32_t suspiciousCount = hasHiddenPrivateWindow ? 2 : 1;
+#endif
+
     if (mConsiderQuitStopper == 0) {
       // there are no windows...
       ferocity = eAttemptQuit;
     }
+#ifdef XP_MACOSX
+    else if (mConsiderQuitStopper == suspiciousCount) {
+      // ... or there is only a hiddenWindow left, and it's useless:
+
+      // Failure shouldn't be fatal, but will abort quit attempt:
+      if (!appShell)
+        return NS_OK;
+
+      bool usefulHiddenWindow;
+      appShell->GetApplicationProvidedHiddenWindow(&usefulHiddenWindow);
+      nsCOMPtr<nsIXULWindow> hiddenWindow;
+      appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
+      // If the remaining windows are useful, we won't quit:
+      nsCOMPtr<nsIXULWindow> hiddenPrivateWindow;
+      if (hasHiddenPrivateWindow) {
+        appShell->GetHiddenPrivateWindow(getter_AddRefs(hiddenPrivateWindow));
+        if ((!hiddenWindow && !hiddenPrivateWindow) || usefulHiddenWindow)
+          return NS_OK;
+      } else if (!hiddenWindow || usefulHiddenWindow) {
+        return NS_OK;
+      }
+
+      ferocity = eAttemptQuit;
+    }
+#endif
   }
 
   nsCOMPtr<nsIObserverService> obsService;
@@ -365,6 +404,10 @@ nsAppStartup::Quit(uint32_t aMode)
 
     if (!mAttemptingQuit) {
       mAttemptingQuit = true;
+#ifdef XP_MACOSX
+      // now even the Mac wants to quit when the last window is closed
+      ExitLastWindowClosingSurvivalArea();
+#endif
       if (obsService)
         obsService->NotifyObservers(nullptr, "quit-application-granted", nullptr);
     }
diff --git a/toolkit/components/thumbnails/PageThumbUtils.jsm b/toolkit/components/thumbnails/PageThumbUtils.jsm
index f91b364800..fb5d67ddb5 100644
--- a/toolkit/components/thumbnails/PageThumbUtils.jsm
+++ b/toolkit/components/thumbnails/PageThumbUtils.jsm
@@ -71,6 +71,18 @@ this.PageThumbUtils = {
       let windowScale = aWindow ? aWindow.devicePixelRatio : systemScale;
       let scale = Math.max(systemScale, windowScale);
 
+#ifdef XP_MACOSX
+      /** *
+       * On retina displays, we can sometimes go down this path
+       * without a window object. In those cases, force 2x scaling
+       * as the system scale doesn't represent the 2x scaling
+       * on OS X.
+       */
+      if (!aWindow) {
+        scale = 2;
+      }
+#endif
+
       /** *
        * THESE VALUES ARE DEFINED IN newtab.css and hard coded.
        * If you change these values from the prefs,
diff --git a/toolkit/components/thumbnails/moz.build b/toolkit/components/thumbnails/moz.build
index 957bc7df0d..92ff2af946 100644
--- a/toolkit/components/thumbnails/moz.build
+++ b/toolkit/components/thumbnails/moz.build
@@ -11,11 +11,11 @@ EXTRA_COMPONENTS += [
 EXTRA_JS_MODULES += [
     'PageThumbs.jsm',
     'PageThumbsWorker.js',
-    'PageThumbUtils.jsm',
 ]
 
 EXTRA_PP_JS_MODULES += [
     'BackgroundPageThumbs.jsm',
+    'PageThumbUtils.jsm',
 ]
 
 JAR_MANIFESTS += ['jar.mn']
diff --git a/toolkit/components/viewsource/content/viewPartialSource.xul b/toolkit/components/viewsource/content/viewPartialSource.xul
index c51744fd21..fdec367b1c 100644
--- a/toolkit/components/viewsource/content/viewPartialSource.xul
+++ b/toolkit/components/viewsource/content/viewPartialSource.xul
@@ -1,8 +1,8 @@
 <?xml version="1.0"?>
-<!-- -*- Mode: XML -*-
- 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/. -->
+# -*- Mode: HTML -*-
+# 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/.
 
 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://global/content/viewSource.css" type="text/css"?>
@@ -99,8 +99,10 @@
                     label="&savePageCmd.label;" accesskey="&savePageCmd.accesskey;"/>
           <menuitem command="cmd_pagesetup" id="menu_pageSetup"
                     label="&pageSetupCmd.label;" accesskey="&pageSetupCmd.accesskey;"/>
+#ifndef XP_MACOSX
           <menuitem command="cmd_printpreview" id="menu_printPreview"
                     label="&printPreviewCmd.label;" accesskey="&printPreviewCmd.accesskey;"/>
+#endif
           <menuitem key="key_print" command="cmd_print" id="menu_print"
                     label="&printCmd.label;" accesskey="&printCmd.accesskey;"/>
           <menuseparator/>
diff --git a/toolkit/components/viewsource/content/viewSource.xul b/toolkit/components/viewsource/content/viewSource.xul
index 3ad45a9d9d..c6ca58234e 100644
--- a/toolkit/components/viewsource/content/viewSource.xul
+++ b/toolkit/components/viewsource/content/viewSource.xul
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-# -*- Mode: XML -*-
+# -*- Mode: HTML -*-
 # 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/.
@@ -50,6 +50,10 @@
            oncommand="document.getElementById('FindToolbar').onFindAgainCommand(false);"/>
   <command id="cmd_findPrevious"
            oncommand="document.getElementById('FindToolbar').onFindAgainCommand(true);"/>
+#ifdef XP_MACOSX
+  <command id="cmd_findSelection"
+           oncommand="document.getElementById('FindToolbar').onFindSelectionCommand();"/>
+#endif
   <command id="cmd_reload" oncommand="viewSourceChrome.reload();"/>
   <command id="cmd_goToLine" oncommand="viewSourceChrome.promptAndGoToLine();" disabled="true"/>
   <command id="cmd_highlightSyntax" oncommand="viewSourceChrome.toggleSyntaxHighlighting();"/>
@@ -85,13 +89,21 @@
     <key id="key_find" key="&findOnCmd.commandkey;" command="cmd_find" modifiers="accel"/>
     <key id="key_findAgain" key="&findAgainCmd.commandkey;" command="cmd_findAgain" modifiers="accel"/>
     <key id="key_findPrevious" key="&findAgainCmd.commandkey;" command="cmd_findPrevious" modifiers="accel,shift"/>
+#ifdef XP_MACOSX
+    <key id="key_findSelection" key="&findSelectionCmd.commandkey;" command="cmd_findSelection" modifiers="accel"/>
+#endif
     <key keycode="&findAgainCmd.commandkey2;" command="cmd_findAgain"/>
     <key keycode="&findAgainCmd.commandkey2;"  command="cmd_findPrevious" modifiers="shift"/>
 
     <key keycode="VK_BACK" command="Browser:Back"/>
     <key keycode="VK_BACK" command="Browser:Forward" modifiers="shift"/>
+#ifndef XP_MACOSX
     <key id="goBackKb" keycode="VK_LEFT" command="Browser:Back" modifiers="alt"/>
     <key id="goForwardKb" keycode="VK_RIGHT" command="Browser:Forward" modifiers="alt"/>
+#else
+    <key id="goBackKb" keycode="VK_LEFT" command="Browser:Back" modifiers="accel" />
+    <key id="goForwardKb" keycode="VK_RIGHT" command="Browser:Forward" modifiers="accel" />
+#endif
 #ifdef XP_UNIX
     <key id="goBackKb2" key="&goBackCmd.commandKey;" command="Browser:Back" modifiers="accel"/>
     <key id="goForwardKb2" key="&goForwardCmd.commandKey;" command="Browser:Forward" modifiers="accel"/>
@@ -138,8 +150,10 @@
                     label="&savePageCmd.label;" accesskey="&savePageCmd.accesskey;"/>
           <menuitem command="cmd_pagesetup" id="menu_pageSetup"
                     label="&pageSetupCmd.label;" accesskey="&pageSetupCmd.accesskey;"/>
+#ifndef XP_MACOSX
           <menuitem command="cmd_printpreview" id="menu_printPreview"
                     label="&printPreviewCmd.label;" accesskey="&printPreviewCmd.accesskey;"/>
+#endif
           <menuitem key="key_print" command="cmd_print" id="menu_print"
                     label="&printCmd.label;" accesskey="&printCmd.accesskey;"/>
           <menuseparator/>
diff --git a/toolkit/components/viewsource/jar.mn b/toolkit/components/viewsource/jar.mn
index 33818ae0db..00a1f19a46 100644
--- a/toolkit/components/viewsource/jar.mn
+++ b/toolkit/components/viewsource/jar.mn
@@ -7,6 +7,6 @@ toolkit.jar:
   content/global/viewSource.js              (content/viewSource.js)
 * content/global/viewSource.xul             (content/viewSource.xul)
   content/global/viewPartialSource.js       (content/viewPartialSource.js)
-  content/global/viewPartialSource.xul      (content/viewPartialSource.xul)
+* content/global/viewPartialSource.xul      (content/viewPartialSource.xul)
   content/global/viewSourceUtils.js         (content/viewSourceUtils.js)
   content/global/viewSource-content.js      (content/viewSource-content.js)
diff --git a/toolkit/content/aboutProfiles.js b/toolkit/content/aboutProfiles.js
index 0e548fd0ff..29c5f67ad7 100644
--- a/toolkit/content/aboutProfiles.js
+++ b/toolkit/content/aboutProfiles.js
@@ -131,6 +131,8 @@ function display(profileData) {
       let button = document.createElement('button');
 #ifdef XP_WIN
       let string = 'winOpenDir2';
+#elifdef XP_MACOSX
+      let string = 'macOpenDir';
 #else
       let string = 'openDir';
 #endif  
diff --git a/toolkit/content/aboutSupport.xhtml b/toolkit/content/aboutSupport.xhtml
index 4ae9927399..8afee18676 100644
--- a/toolkit/content/aboutSupport.xhtml
+++ b/toolkit/content/aboutSupport.xhtml
@@ -156,8 +156,12 @@
 #ifdef XP_WIN
               &aboutSupport.appBasicsProfileDirWinMac;
 #else
+#ifdef XP_MACOSX
+              &aboutSupport.appBasicsProfileDirWinMac;
+#else
               &aboutSupport.appBasicsProfileDir;
 #endif
+#endif
             </th>
 
             <td>
@@ -165,8 +169,12 @@
 #ifdef XP_WIN
                 &aboutSupport.showWin2.label;
 #else
+#ifdef XP_MACOSX
+                &aboutSupport.showMac.label;
+#else
                 &aboutSupport.showDir.label;
 #endif
+#endif
                </button>
             </td>
           </tr>
diff --git a/toolkit/content/customizeToolbar.js b/toolkit/content/customizeToolbar.js
index 1775d9f52a..05151b905d 100644
--- a/toolkit/content/customizeToolbar.js
+++ b/toolkit/content/customizeToolbar.js
@@ -212,6 +212,10 @@ function wrapToolbarItems()
 {
   forEachCustomizableToolbar(function (toolbar) {
     Array.forEach(toolbar.childNodes, function (item) {
+#ifdef XP_MACOSX
+      if (item.firstChild && item.firstChild.localName == "menubar")
+        return;
+#endif
       if (isToolbarItem(item)) {
         let wrapper = wrapToolbarItem(item);
         cleanupItemForToolbar(item, wrapper);
diff --git a/toolkit/content/dialogOverlay.xul b/toolkit/content/dialogOverlay.xul
index 9d4d8b6138..09e00613e1 100644
--- a/toolkit/content/dialogOverlay.xul
+++ b/toolkit/content/dialogOverlay.xul
@@ -1,11 +1,11 @@
 <?xml version="1.0"?>
-<!-- -*- Mode: XML -*-
- 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/.
-
- WARNING!!! This file is obsoleted by the dialog.xml widget
--->
+# -*- Mode: HTML -*-
+# 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/.
+#
+# WARNING!!! This file is obsoleted by the dialog.xml widget
+#
 
 <!DOCTYPE overlay SYSTEM "chrome://global/locale/dialogOverlay.dtd">
 
@@ -14,6 +14,44 @@
 
   <script type="application/javascript" src="chrome://global/content/dialogOverlay.js"/>
 
+#ifdef XP_MACOSX
+#
+  <hbox id="okCancelButtons">
+    <spacer flex="1"/>
+    <button class="exit-dialog" id="Button3" label="" collapsed="true" oncommand="doButton3();"/>
+    <button class="exit-dialog" id="Button2" label="" collapsed="true" oncommand="doButton2();"/>
+    <button class="exit-dialog" id="cancel" label="&cancelButton.label;" oncommand="doCancelButton();"/>
+    <button class="right exit-dialog" id="ok" default="true" label="&okButton.label;" oncommand="doOKButton();"/>
+  </hbox>
+
+  <hbox id="okCancelHelpButtons">
+    <button class="exit-dialog" id="help" label="&helpButton.label;" oncommand="doHelpButton();"/>
+    <spacer flex="1"/>
+    <button class="exit-dialog" id="Button3" label="" collapsed="true" oncommand="doButton3();"/>
+    <button class="exit-dialog" id="Button2" label="" collapsed="true" oncommand="doButton2();"/>
+    <button class="exit-dialog" id="cancel" label="&cancelButton.label;" oncommand="doCancelButton();"/>
+    <button class="right exit-dialog" id="ok" default="true" label="&okButton.label;" oncommand="doOKButton();"/>
+  </hbox>
+
+  <hbox id="okCancelButtonsRight">
+    <spacer flex="1"/>
+    <button class="exit-dialog" id="Button3" label="" collapsed="true" oncommand="doButton3();"/>
+    <button class="exit-dialog" id="Button2" label="" collapsed="true" oncommand="doButton2();"/>
+    <button class="exit-dialog" id="cancel" label="&cancelButton.label;" oncommand="doCancelButton();"/>
+    <button class="right exit-dialog" id="ok" default="true" label="&okButton.label;" oncommand="doOKButton();"/>
+  </hbox>
+
+  <hbox id="okCancelHelpButtonsRight">
+    <button class="exit-dialog" id="help" label="&helpButton.label;" oncommand="doHelpButton();"/>
+    <spacer flex="1"/>
+    <button class="exit-dialog" id="Button3" label="" collapsed="true" oncommand="doButton3();"/>
+    <button class="exit-dialog" id="Button2" label="" collapsed="true" oncommand="doButton2();"/>
+    <button class="exit-dialog" id="cancel" label="&cancelButton.label;" oncommand="doCancelButton();"/>
+    <button class="right exit-dialog" id="ok" default="true" label="&okButton.label;" oncommand="doOKButton();"/>
+  </hbox>
+#
+#else
+#
   <hbox id="okCancelButtons">
     <spacer flex="1"/>
     <button class="right exit-dialog" id="ok" label="&okButton.label;" default="true" oncommand="doOKButton();"/> 
@@ -49,10 +87,15 @@
     <button class="exit-dialog" id="cancel" label="&cancelButton.label;" oncommand="doCancelButton();"/>
     <button class="exit-dialog" id="help" label="&helpButton.label;" oncommand="doHelpButton();"/>
   </hbox>
+#endif
 
   <keyset id="dialogKeys">
     <key keycode="VK_RETURN" oncommand="if (!document.getElementById('ok').disabled) doOKButton();"/>
     <key keycode="VK_ESCAPE" oncommand="doCancelButton();"/>
+#ifdef XP_MACOSX
+    <key key="." modifiers="meta" oncommand="doCancelButton();"/>
+#
+#endif
   </keyset>
 
 </overlay>
diff --git a/toolkit/content/globalOverlay.js b/toolkit/content/globalOverlay.js
index d5ee131916..d8467f0a12 100644
--- a/toolkit/content/globalOverlay.js
+++ b/toolkit/content/globalOverlay.js
@@ -4,6 +4,12 @@
 
 function closeWindow(aClose, aPromptFunction)
 {
+#ifdef XP_MACOSX
+  // Closing the last window doesn't quit the application on OS X.
+  if (typeof(aPromptFunction) == "function" && !aPromptFunction()) {
+    return false;
+  }
+#else
   var windowCount = 0;
   var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]
                      .getService(Components.interfaces.nsIWindowMediator);
@@ -23,6 +29,7 @@ function closeWindow(aClose, aPromptFunction)
     return false;
   if (windowCount != 1 && typeof(aPromptFunction) == "function" && !aPromptFunction())
     return false;
+#endif
 
   if (aClose) {
     window.close();
diff --git a/toolkit/content/jar.mn b/toolkit/content/jar.mn
index 1f1c880397..6494645086 100644
--- a/toolkit/content/jar.mn
+++ b/toolkit/content/jar.mn
@@ -15,7 +15,7 @@ toolkit.jar:
 #ifdef MOZ_OFFICIAL_BRANDING
 *  content/global/aboutRights.xhtml
 #else
-   content/global/aboutRights.xhtml           (aboutRights-unbranded.xhtml)
+*  content/global/aboutRights.xhtml           (aboutRights-unbranded.xhtml)
 #endif
    content/global/aboutNetworking.js
    content/global/aboutNetworking.xhtml
@@ -38,7 +38,7 @@ toolkit.jar:
 *  content/global/buildconfig.html
 *  content/global/contentAreaUtils.js
    content/global/customizeToolbar.css
-   content/global/customizeToolbar.js
+*  content/global/customizeToolbar.js
    content/global/customizeToolbar.xul
    content/global/datepicker.xhtml
    content/global/editMenuOverlay.js
@@ -47,7 +47,7 @@ toolkit.jar:
 *  content/global/finddialog.xul
    content/global/findUtils.js
    content/global/filepicker.properties
-   content/global/globalOverlay.js
+*  content/global/globalOverlay.js
    content/global/mozilla.xhtml
 #ifdef MOZ_PHOENIX
    content/global/logopage.xhtml
@@ -63,7 +63,7 @@ toolkit.jar:
    content/global/treeUtils.js
    content/global/viewZoomOverlay.js
    content/global/globalOverlay.xul
-   content/global/dialogOverlay.xul
+*  content/global/dialogOverlay.xul
    content/global/dialogOverlay.js
    content/global/inlineSpellCheckUI.js
    content/global/nsClipboard.js
@@ -85,7 +85,7 @@ toolkit.jar:
    content/global/bindings/editor.xml          (widgets/editor.xml)
    content/global/bindings/expander.xml        (widgets/expander.xml)
    content/global/bindings/filefield.xml       (widgets/filefield.xml)
-   content/global/bindings/findbar.xml         (widgets/findbar.xml)
+*  content/global/bindings/findbar.xml         (widgets/findbar.xml)
    content/global/bindings/general.xml         (widgets/general.xml)
    content/global/bindings/groupbox.xml        (widgets/groupbox.xml)
    content/global/bindings/listbox.xml         (widgets/listbox.xml)
@@ -114,10 +114,13 @@ toolkit.jar:
    content/global/bindings/timepicker.js       (widgets/timepicker.js)
    content/global/bindings/toolbar.xml         (widgets/toolbar.xml)
    content/global/bindings/toolbarbutton.xml   (widgets/toolbarbutton.xml)
-   content/global/bindings/tree.xml            (widgets/tree.xml)
+*  content/global/bindings/tree.xml            (widgets/tree.xml)
    content/global/bindings/videocontrols.xml   (widgets/videocontrols.xml)
    content/global/bindings/videocontrols.css   (widgets/videocontrols.css)
 *  content/global/bindings/wizard.xml          (widgets/wizard.xml)
+#ifdef XP_MACOSX
+   content/global/macWindowMenu.js
+#endif
    content/global/svg/svgBindings.xml          (/layout/svg/resources/content/svgBindings.xml)
    content/global/gmp-sources/openh264.json    (gmp-sources/openh264.json)
    content/global/gmp-sources/widevinecdm.json (gmp-sources/widevinecdm.json)
diff --git a/toolkit/content/license.html b/toolkit/content/license.html
index 94d39959b2..0de306f36e 100644
--- a/toolkit/content/license.html
+++ b/toolkit/content/license.html
@@ -5341,7 +5341,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 </pre>
 
 
-#if defined(XP_WIN) || defined(XP_LINUX)
+#if defined(XP_WIN) || defined(XP_MACOSX) || defined(XP_LINUX)
 
     <hr>
 
diff --git a/toolkit/content/macWindowMenu.inc b/toolkit/content/macWindowMenu.inc
new file mode 100644
index 0000000000..c345ad8b7f
--- /dev/null
+++ b/toolkit/content/macWindowMenu.inc
@@ -0,0 +1,40 @@
+    <script type="application/javascript" src="chrome://global/content/macWindowMenu.js"/>
+    <commandset id="baseMenuCommandSet">
+        <command id="minimizeWindow"
+                 label="&minimizeWindow.label;"
+                 oncommand="window.minimize();" />
+        <command id="zoomWindow"
+                 label="&zoomWindow.label;"
+                 oncommand="zoomWindow();" />
+    </commandset>
+    <keyset id="baseMenuKeyset">
+        <key id="key_minimizeWindow"
+             command="minimizeWindow"
+             key="&minimizeWindow.key;"
+             modifiers="accel"/>
+    </keyset>
+    <menu id="windowMenu"
+          label="&windowMenu.label;"
+          datasources="rdf:window-mediator" ref="NC:WindowMediatorRoot"
+          onpopupshowing="macWindowMenuDidShow();"
+          hidden="false">
+        <template>
+        <rule>
+            <menupopup>
+                <menuitem uri="rdf:*"
+                          label="rdf:http://home.netscape.com/NC-rdf#Name"
+                          type="radio"
+                          name="windowList"
+                          oncommand="ShowWindowFromResource(event.target)"/>
+            </menupopup>
+        </rule>
+        </template>
+        <menupopup id="windowPopup">
+            <menuitem command="minimizeWindow" key="key_minimizeWindow"/>
+            <menuitem command="zoomWindow"/>
+            <!-- decomment when "BringAllToFront" is implemented
+                <menuseparator/>
+                <menuitem label="&bringAllToFront.label;" disabled="true"/> -->
+            <menuseparator id="sep-window-list"/>
+        </menupopup>
+    </menu>
diff --git a/toolkit/content/macWindowMenu.js b/toolkit/content/macWindowMenu.js
new file mode 100644
index 0000000000..46654c4f8a
--- /dev/null
+++ b/toolkit/content/macWindowMenu.js
@@ -0,0 +1,51 @@
+// -*- indent-tabs-mode: nil; js-indent-level: 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/. */
+
+function macWindowMenuDidShow()
+{
+  var windowManagerDS =
+    Components.classes['@mozilla.org/rdf/datasource;1?name=window-mediator']
+              .getService(Components.interfaces.nsIWindowDataSource);
+  var sep = document.getElementById("sep-window-list");
+  // Using double parens to avoid warning
+  while ((sep = sep.nextSibling)) {
+    var url = sep.getAttribute('id');
+    var win = windowManagerDS.getWindowForResource(url);
+    if (win.document.documentElement.getAttribute("inwindowmenu") == "false")
+      sep.hidden = true;
+    else if (win == window)
+      sep.setAttribute("checked", "true");
+  }
+}
+
+function toOpenWindow( aWindow )
+{
+  // deminiaturize the window, if it's in the Dock
+  if (aWindow.windowState == STATE_MINIMIZED)
+    aWindow.restore();
+  aWindow.document.commandDispatcher.focusedWindow.focus();
+}
+
+function ShowWindowFromResource( node )
+{
+  var windowManagerDS =
+    Components.classes['@mozilla.org/rdf/datasource;1?name=window-mediator']
+              .getService(Components.interfaces.nsIWindowDataSource);
+
+  var desiredWindow = null;
+  var url = node.getAttribute('id');
+  desiredWindow = windowManagerDS.getWindowForResource( url );
+  if (desiredWindow)
+    toOpenWindow(desiredWindow);
+}
+
+function zoomWindow()
+{
+  if (window.windowState == STATE_NORMAL)
+    window.maximize();
+  else
+    window.restore();
+}
diff --git a/toolkit/content/widgets/dialog.xml b/toolkit/content/widgets/dialog.xml
index aff1621965..d83570ac0f 100644
--- a/toolkit/content/widgets/dialog.xml
+++ b/toolkit/content/widgets/dialog.xml
@@ -422,11 +422,15 @@
         if (!event.defaultPrevented)
           this.cancelDialog();
       </handler>
+#ifdef XP_MACOSX
+      <handler event="keypress" key="." modifiers="meta" phase="capturing" action="this.cancelDialog();"/>
+#else
       <handler event="focus" phase="capturing">
         var btn = this.getButton(this.defaultButton);
         if (btn)
           btn.setAttribute("default", event.originalTarget == btn || !(event.originalTarget instanceof Components.interfaces.nsIDOMXULButtonElement));
       </handler>
+#endif
     </handlers>
 
   </binding>
diff --git a/toolkit/content/widgets/findbar.xml b/toolkit/content/widgets/findbar.xml
index aae799554d..c312a6a25a 100644
--- a/toolkit/content/widgets/findbar.xml
+++ b/toolkit/content/widgets/findbar.xml
@@ -1232,6 +1232,39 @@
         ]]></body>
       </method>
 
+#ifdef XP_MACOSX
+      <!--
+        - Fetches the currently selected text and sets that as the text to search
+        - next. This is a MacOS specific feature.
+      -->
+      <method name="onFindSelectionCommand">
+        <body><![CDATA[
+          let searchString = this.browser.finder.setSearchStringToSelection();
+          if (searchString)
+            this._findField.value = searchString;
+        ]]></body>
+      </method>
+
+      <method name="_onFindFieldFocus">
+        <body><![CDATA[
+          let prefsvc = this._prefsvc;
+          const kPref = "accessibility.typeaheadfind.prefillwithselection";
+          if (this.prefillWithSelection && prefsvc.getBoolPref(kPref))
+            return;
+
+          let clipboardSearchString = this._browser.finder.clipboardSearchString;
+          if (clipboardSearchString && this._findField.value != clipboardSearchString &&
+              !this._findField._willfullyDeleted) {
+            this._findField.value = clipboardSearchString;
+            this._findField._hadValue = true;
+            // Changing the search string makes the previous status invalid, so
+            // we better clear it here.
+            this._updateStatusUI();
+          }
+        ]]></body>
+      </method>
+#endif
+
       <!--
         - This handles all the result changes for both
         - type-ahead-find and highlighting.
diff --git a/toolkit/content/widgets/optionsDialog.xml b/toolkit/content/widgets/optionsDialog.xml
index efd20663e5..f0cdba62f2 100644
--- a/toolkit/content/widgets/optionsDialog.xml
+++ b/toolkit/content/widgets/optionsDialog.xml
@@ -11,6 +11,7 @@
   <binding id="optionsDialog" 
            extends="chrome://global/content/bindings/dialog.xml#dialog">
      <content>
+#ifndef XP_MACOSX
        <xul:hbox flex="1">
          <xul:categoryBox anonid="prefsCategories">
            <children/>
@@ -20,6 +21,16 @@
            <xul:iframe anonid="panelFrame" name="panelFrame" style="width: 0px;" flex="1"/>
          </xul:vbox>
        </xul:hbox>
+#else
+       <xul:vbox flex="1">
+         <xul:categoryBox anonid="prefsCategories">
+           <children/>
+         </xul:categoryBox>
+         <xul:vbox flex="1">
+           <xul:iframe anonid="panelFrame" name="panelFrame" style="width: 0px;" flex="1"/>
+         </xul:vbox>
+       </xul:vbox>
+#endif
      </content>
      
      <implementation>
diff --git a/toolkit/content/widgets/preferences.xml b/toolkit/content/widgets/preferences.xml
index f7cb109488..11de032462 100644
--- a/toolkit/content/widgets/preferences.xml
+++ b/toolkit/content/widgets/preferences.xml
@@ -1146,7 +1146,11 @@
       </handler>
 
       <handler event="keypress"
+#ifdef XP_MACOSX
+               key="&openHelpMac.commandkey;" modifiers="accel"
+#else
                keycode="&openHelp.commandkey;"
+#endif
                phase="capturing">
       <![CDATA[
         var helpButton = this.getButton("help");
diff --git a/toolkit/content/widgets/tree.xml b/toolkit/content/widgets/tree.xml
index 19a1fa7727..aa17172575 100644
--- a/toolkit/content/widgets/tree.xml
+++ b/toolkit/content/widgets/tree.xml
@@ -79,11 +79,11 @@
       <property name="treeBoxObject"
                 onget="return this.boxObject;"
                 readonly="true"/>
-<!-- contentView is obsolete (see bug 202391) -->
+# contentView is obsolete (see bug 202391)
       <property name="contentView"
                 onget="return this.view; /*.QueryInterface(Components.interfaces.nsITreeContentView)*/"
                 readonly="true"/>
-<!-- builderView is obsolete (see bug 202393) -->
+# builderView is obsolete (see bug 202393)
       <property name="builderView"
                 onget="return this.view; /*.QueryInterface(Components.interfaces.nsIXULTreeBuilder)*/"
                 readonly="true"/>
@@ -774,6 +774,7 @@
           event.preventDefault();
         }
       </handler>
+#ifndef XP_MACOSX
       <!-- Use F2 key to enter text editing. -->
       <handler event="keydown" keycode="VK_F2">
         <![CDATA[
@@ -785,6 +786,7 @@
             event.preventDefault();
         ]]>
       </handler>
+#endif // XP_MACOSX
 
       <handler event="keydown" keycode="VK_ESCAPE">
         <![CDATA[
diff --git a/toolkit/content/widgets/wizard.xml b/toolkit/content/widgets/wizard.xml
index eb812f0652..3a8ec2cfef 100644
--- a/toolkit/content/widgets/wizard.xml
+++ b/toolkit/content/widgets/wizard.xml
@@ -465,6 +465,54 @@
     </implementation>
   </binding>
 
+#ifdef XP_MACOSX
+  <binding id="wizard-header" extends="chrome://global/content/bindings/wizard.xml#wizard-base">
+    <content>
+      <xul:stack class="wizard-header-stack" flex="1">
+        <xul:vbox class="wizard-header-box-1">
+          <xul:vbox class="wizard-header-box-text">
+            <xul:label class="wizard-header-label" xbl:inherits="xbl:text=label"/>
+          </xul:vbox>
+        </xul:vbox>
+        <xul:hbox class="wizard-header-box-icon">
+          <xul:spacer flex="1"/>
+          <xul:image class="wizard-header-icon" xbl:inherits="src=iconsrc"/>
+        </xul:hbox>
+      </xul:stack>
+    </content>
+  </binding>
+
+  <binding id="wizard-buttons" extends="chrome://global/content/bindings/wizard.xml#wizard-base">
+    <content>
+      <xul:vbox flex="1">
+        <xul:hbox class="wizard-buttons-btm">
+          <xul:button class="wizard-button" dlgtype="extra1" hidden="true"/>
+          <xul:button class="wizard-button" dlgtype="extra2" hidden="true"/>
+          <xul:button label="&button-cancel-mac.label;" class="wizard-button" dlgtype="cancel"/>
+          <xul:spacer flex="1"/>
+          <xul:button label="&button-back-mac.label;" accesskey="&button-back-mac.accesskey;"
+                      class="wizard-button wizard-nav-button" dlgtype="back"/>
+          <xul:button label="&button-next-mac.label;" accesskey="&button-next-mac.accesskey;"
+                      class="wizard-button wizard-nav-button" dlgtype="next"
+                      default="true" xbl:inherits="hidden=lastpage" />
+          <xul:button label="&button-finish-mac.label;" class="wizard-button"
+                      dlgtype="finish" default="true" xbl:inherits="hidden=hidefinishbutton" />
+        </xul:hbox>
+      </xul:vbox>
+    </content>
+
+    <implementation>
+      <method name="onPageChange">
+        <body><![CDATA[
+          this.setAttribute("hidefinishbutton", !(this.getAttribute("lastpage") == "true"));
+        ]]></body>
+      </method>
+    </implementation>
+
+  </binding>
+
+#else
+
   <binding id="wizard-header" extends="chrome://global/content/bindings/wizard.xml#wizard-base">
     <content>
       <xul:hbox class="wizard-header-box-1" flex="1">
@@ -554,5 +602,6 @@
       </property>
     </implementation>
   </binding>
+#endif
 
 </bindings>
diff --git a/toolkit/content/xul.css b/toolkit/content/xul.css
index 7c16cab703..0aa0d3a217 100644
--- a/toolkit/content/xul.css
+++ b/toolkit/content/xul.css
@@ -243,6 +243,11 @@ caption {
 
 /******** draggable elements *********/
 
+%ifdef XP_MACOSX
+titlebar,
+toolbar:not([nowindowdrag="true"]):not([customizing="true"]),
+statusbar:not([nowindowdrag="true"]),
+%endif
 windowdragbox {
   -moz-window-dragging: drag;
 }
@@ -283,6 +288,12 @@ toolbar[customizing="true"][hidden="true"] {
   display: -moz-box;
 }
 
+%ifdef XP_MACOSX
+toolbar[type="menubar"] {
+  min-height: 0 !important;
+  border: 0 !important;
+}
+%else
 toolbar[type="menubar"][autohide="true"] {
   -moz-binding: url("chrome://global/content/bindings/toolbar.xml#toolbar-menubar-autohide");
   overflow: hidden;
@@ -294,6 +305,7 @@ toolbar[type="menubar"][autohide="true"][inactive="true"]:not([customizing="true
   -moz-appearance: none !important;
   border-style: none !important;
 }
+%endif
 
 %ifdef MOZ_WIDGET_GTK
 window[shellshowingmenubar="true"] menubar,
@@ -487,9 +499,15 @@ panel[arrowposition="start_after"]:-moz-locale-dir(rtl) {
 
 %endif
 
+%ifdef XP_MACOSX
+.statusbar-resizerpanel {
+  display: none;
+}
+%else
 window[sizemode="maximized"] statusbarpanel.statusbar-resizerpanel {
   visibility: collapse;
 }
+%endif
 
 /******** grid **********/
 
@@ -1000,6 +1018,9 @@ autorepeatbutton {
 
 statusbar {
   -moz-binding: url("chrome://global/content/bindings/general.xml#statusbar");
+%ifdef XP_MACOSX
+  padding-right: 14px;
+%endif
 }
 
 statusbarpanel {
diff --git a/toolkit/modules/AppConstants.jsm b/toolkit/modules/AppConstants.jsm
index 40a630a445..ba94f4a3fc 100644
--- a/toolkit/modules/AppConstants.jsm
+++ b/toolkit/modules/AppConstants.jsm
@@ -105,6 +105,8 @@ this.AppConstants = Object.freeze({
   "linux",
 #elif XP_WIN
   "win",
+#elif XP_MACOSX
+  "macosx",
 #elif XP_LINUX
   "linux",
 #else
diff --git a/toolkit/modules/LightweightThemeConsumer.jsm b/toolkit/modules/LightweightThemeConsumer.jsm
index 9419fdcf23..4010a9ff22 100644
--- a/toolkit/modules/LightweightThemeConsumer.jsm
+++ b/toolkit/modules/LightweightThemeConsumer.jsm
@@ -147,6 +147,29 @@ LightweightThemeConsumer.prototype = {
         footer.removeAttribute("lwthemefooter");
     }
 
+#if defined(XP_MACOSX) && defined(MOZ_CAN_DRAW_IN_TITLEBAR)
+    // On OS X, we extend the lightweight theme into the titlebar, which means setting
+    // the chromemargin attribute. Some XUL applications already draw in the titlebar,
+    // so we need to save the chromemargin value before we overwrite it with the value
+    // that lets us draw in the titlebar. We stash this value on the root attribute so
+    // that XUL applications have the ability to invalidate the saved value.
+    if (stateChanging) {
+      if (!root.hasAttribute("chromemargin-nonlwtheme")) {
+        root.setAttribute("chromemargin-nonlwtheme", root.getAttribute("chromemargin"));
+      }
+
+      if (active) {
+        root.setAttribute("chromemargin", "0,-1,-1,-1");
+      } else {
+        let defaultChromemargin = root.getAttribute("chromemargin-nonlwtheme");
+        if (defaultChromemargin) {
+          root.setAttribute("chromemargin", defaultChromemargin);
+        } else {
+          root.removeAttribute("chromemargin");
+        }
+      }
+    }
+#endif
     Services.obs.notifyObservers(this._win, "lightweight-theme-window-updated",
                                  JSON.stringify(aData));
   }
diff --git a/toolkit/modules/UpdateUtils.jsm b/toolkit/modules/UpdateUtils.jsm
index 5e3a2e100a..5acf395d3d 100644
--- a/toolkit/modules/UpdateUtils.jsm
+++ b/toolkit/modules/UpdateUtils.jsm
@@ -168,6 +168,17 @@ XPCOMUtils.defineLazyGetter(UpdateUtils, "ABI", function() {
     Cu.reportError("XPCOM ABI unknown");
   }
 
+#ifdef XP_MACOSX
+  // Mac universal build should report a different ABI than either macppc
+  // or mactel.
+  let macutils = Cc["@mozilla.org/xpcom/mac-utils;1"].
+                 getService(Ci.nsIMacUtils);
+
+  if (macutils.isUniversalBinary) {
+    abi += "-u-" + macutils.architecturesInBinary;
+  }
+#endif
+
   return abi;
 });
 
diff --git a/toolkit/modules/WindowDraggingUtils.jsm b/toolkit/modules/WindowDraggingUtils.jsm
index 5be8814de1..a7986c8b4a 100644
--- a/toolkit/modules/WindowDraggingUtils.jsm
+++ b/toolkit/modules/WindowDraggingUtils.jsm
@@ -2,7 +2,7 @@
  * 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/. */
 
-#if defined(XP_WIN)
+#if defined(XP_WIN) || defined(XP_MACOSX)
 const HAVE_CSS_WINDOW_DRAG_SUPPORT = true;
 #else
 const HAVE_CSS_WINDOW_DRAG_SUPPORT = false;
diff --git a/toolkit/modules/moz.build b/toolkit/modules/moz.build
index 836fd66b36..8509eb7cd3 100644
--- a/toolkit/modules/moz.build
+++ b/toolkit/modules/moz.build
@@ -103,7 +103,7 @@ EXTRA_PP_JS_MODULES += [
 ]
 
 
-EXTRA_JS_MODULES += [
+EXTRA_PP_JS_MODULES += [
     'LightweightThemeConsumer.jsm',
 ]
 
diff --git a/toolkit/mozapps/downloads/content/downloads.xul b/toolkit/mozapps/downloads/content/downloads.xul
index b5ca87a0c2..5ca9eec2d4 100644
--- a/toolkit/mozapps/downloads/content/downloads.xul
+++ b/toolkit/mozapps/downloads/content/downloads.xul
@@ -1,13 +1,15 @@
 <?xml version="1.0"?>
 
-# -*- Mode: XML; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+# -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 # 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/.
 
 #ifdef XP_UNIX
+#ifndef XP_MACOSX
 #define XP_GNOME 1
 #endif
+#endif
 
 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
 <?xml-stylesheet href="chrome://mozapps/content/downloads/downloads.css"?>
@@ -50,6 +52,9 @@
     <key keycode="VK_RETURN" oncommand="doDefaultForSelected();"/>
     <key id="key_pauseResume" key=" " oncommand="performCommand('cmd_pauseResume');"/>
     <key id="key_removeFromList"  keycode="VK_DELETE" oncommand="performCommand('cmd_removeFromList');"/>
+#ifdef XP_MACOSX
+    <key id="key_removeFromList2" keycode="VK_BACK" oncommand="performCommand('cmd_removeFromList');"/>
+#endif
     <key id="key_close"   key="&cmd.close.commandKey;"  oncommand="closeWindow(true);"    modifiers="accel"/>
 #ifdef XP_GNOME
     <key id="key_close2"  key="&cmd.close2Unix.commandKey;" oncommand="closeWindow(true);" modifiers="accel,shift"/>
@@ -95,8 +100,13 @@
               oncommand="performCommand('cmd_open');"
               cmd="cmd_open"/>
     <menuitem id="menuitem_show"
+#ifdef XP_MACOSX
+              label="&cmd.showMac.label;"
+              accesskey="&cmd.showMac.accesskey;"
+#else
               label="&cmd.show.label;"
               accesskey="&cmd.show.accesskey;"
+#endif
               oncommand="performCommand('cmd_show');"
               cmd="cmd_show"/>
 
diff --git a/toolkit/mozapps/downloads/content/unknownContentType.xul b/toolkit/mozapps/downloads/content/unknownContentType.xul
index 42d356e9f9..af8b7b016a 100644
--- a/toolkit/mozapps/downloads/content/unknownContentType.xul
+++ b/toolkit/mozapps/downloads/content/unknownContentType.xul
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-# -*- Mode: XML; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+# -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 # 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/.
@@ -68,7 +68,11 @@
             <hbox id="openHandlerBox" flex="1" align="center"/>
             <hbox flex="1" align="center">
               <button id="chooseButton" oncommand="dialog.chooseApp();"
+#ifdef XP_MACOSX
+                      label="&chooseHandlerMac.label;" accesskey="&chooseHandlerMac.accesskey;"/>
+#else
                       label="&chooseHandler.label;" accesskey="&chooseHandler.accesskey;"/>
+#endif
             </hbox>
           </deck>
         </hbox>
diff --git a/toolkit/mozapps/downloads/nsHelperAppDlg.js b/toolkit/mozapps/downloads/nsHelperAppDlg.js
index 0e5cfdaf0e..90d38c90b0 100644
--- a/toolkit/mozapps/downloads/nsHelperAppDlg.js
+++ b/toolkit/mozapps/downloads/nsHelperAppDlg.js
@@ -675,7 +675,11 @@ nsUnknownContentTypeDialog.prototype = {
 
   // getPath:
   getPath: function (aFile) {
+#ifdef XP_MACOSX
+      return aFile.leafName || aFile.path;
+#else
     return aFile.path;
+#endif
   },
 
   // initAppAndSaveToDiskValues:
@@ -983,6 +987,12 @@ nsUnknownContentTypeDialog.prototype = {
         return file.getVersionInfoField("FileDescription");
       } catch (e) {}
     }
+#elifdef XP_MACOSX
+    if (file instanceof Components.interfaces.nsILocalFileMac) {
+      try {
+        return file.bundleDisplayName;
+      } catch (e) {}
+    }
 #endif
 
     return file.leafName;
diff --git a/toolkit/mozapps/extensions/GMPUtils.jsm b/toolkit/mozapps/extensions/GMPUtils.jsm
index 593fc3c8da..3c691610d5 100644
--- a/toolkit/mozapps/extensions/GMPUtils.jsm
+++ b/toolkit/mozapps/extensions/GMPUtils.jsm
@@ -39,6 +39,11 @@ this.GMPUtils = {
    *          The plugin to check.
    */
   isPluginHidden: function(aPlugin) {
+    if (this._is32bitModeMacOS()) {
+      // GMPs are hidden on MacOS when running in 32 bit mode.
+      // See bug 1291537.
+      return true;
+    }
     if (!aPlugin.isEME) {
       return false;
     }
@@ -66,7 +71,7 @@ this.GMPUtils = {
     }
     if (aPlugin.id == WIDEVINE_ID) {
 
-#if defined(XP_WIN) || defined(XP_LINUX)
+#if defined(XP_WIN) || defined(XP_LINUX) || defined(XP_MACOSX)
       // The Widevine plugin is available for Windows versions Vista and later,
       // Mac OSX, and Linux.
       return true;
@@ -78,6 +83,14 @@ this.GMPUtils = {
     return true;
   },
 
+  _is32bitModeMacOS: function() {
+#ifdef XP_MACOSX
+    return Services.appinfo.XPCOMABI.split("-")[0] == "x86";
+#else
+    return false;
+#endif
+  },
+
   /**
    * Checks whether or not a given plugin is visible in the addons manager
    * UI and the "enable DRM" notification box. This can be used to test
diff --git a/toolkit/mozapps/extensions/content/extensions.js b/toolkit/mozapps/extensions/content/extensions.js
index fe84bc4602..2ca3898f17 100644
--- a/toolkit/mozapps/extensions/content/extensions.js
+++ b/toolkit/mozapps/extensions/content/extensions.js
@@ -1878,7 +1878,11 @@ var gHeader = {
 
     // XXXunf Temporary until bug 371900 is fixed.
     let key = document.getElementById("focusSearch").getAttribute("key");
+#ifdef XP_MACOSX
+    let keyModifier = aEvent.metaKey;
+#else
     let keyModifier = aEvent.ctrlKey;
+#endif
     if (String.fromCharCode(aEvent.charCode) == key && keyModifier) {
       this.focusSearchBox();
       return;
diff --git a/toolkit/mozapps/extensions/content/update.xul b/toolkit/mozapps/extensions/content/update.xul
index 9f5f35196e..094651fa5f 100644
--- a/toolkit/mozapps/extensions/content/update.xul
+++ b/toolkit/mozapps/extensions/content/update.xul
@@ -1,9 +1,9 @@
 <?xml version="1.0"?>
 
-<!-- -*- Mode: XML; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- -->
-<!-- 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/. -->
+# -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+# 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/.
 
 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?> 
 <?xml-stylesheet href="chrome://mozapps/skin/extensions/update.css" type="text/css"?> 
@@ -100,7 +100,11 @@
                 oncommand="gUpdateWizard.shouldAutoCheck = this.checked;"/>
     </vbox>
     <separator flex="1"/>
+#ifndef XP_MACOSX
     <label>&clickFinish.label;</label>
+#else
+    <label>&clickFinish.labelMac;</label>
+#endif
     <separator class="thin"/>
   </wizardpage>
 
@@ -140,7 +144,11 @@
       <description flex="1">&installerrors.intro.label;</description>
     </hbox>
     <separator flex="1"/>
+#ifndef XP_MACOSX
     <label>&clickFinish.label;</label>
+#else
+    <label>&clickFinish.labelMac;</label>
+#endif
     <separator class="thin"/>
   </wizardpage>
   
@@ -153,7 +161,11 @@
       <description flex="1">&adminDisabled.warning.label;</description>
     </hbox>
     <separator flex="1"/>
+#ifndef XP_MACOSX
     <label>&clickFinish.label;</label>
+#else
+    <label>&clickFinish.labelMac;</label>
+#endif
     <separator class="thin"/>
   </wizardpage>
 
@@ -172,7 +184,11 @@
                 oncommand="gUpdateWizard.shouldAutoCheck = this.checked;"/>
     </vbox>
     <separator flex="1"/>
+#ifndef XP_MACOSX
     <label>&clickFinish.label;</label>
+#else
+    <label>&clickFinish.labelMac;</label>
+#endif
     <separator class="thin"/>
   </wizardpage>
   
diff --git a/toolkit/mozapps/extensions/jar.mn b/toolkit/mozapps/extensions/jar.mn
index 878be4df13..e95d93ca02 100644
--- a/toolkit/mozapps/extensions/jar.mn
+++ b/toolkit/mozapps/extensions/jar.mn
@@ -21,7 +21,7 @@ toolkit.jar:
   content/mozapps/extensions/selectAddons.xml                   (content/selectAddons.xml)
   content/mozapps/extensions/selectAddons.js                    (content/selectAddons.js)
   content/mozapps/extensions/selectAddons.css                   (content/selectAddons.css)
-  content/mozapps/extensions/update.xul                         (content/update.xul)
+* content/mozapps/extensions/update.xul                         (content/update.xul)
   content/mozapps/extensions/update.js                          (content/update.js)
   content/mozapps/extensions/eula.xul                           (content/eula.xul)
   content/mozapps/extensions/eula.js                            (content/eula.js)
diff --git a/toolkit/mozapps/update/common/updatecommon.cpp b/toolkit/mozapps/update/common/updatecommon.cpp
index 17a57eae38..aff7d72602 100644
--- a/toolkit/mozapps/update/common/updatecommon.cpp
+++ b/toolkit/mozapps/update/common/updatecommon.cpp
@@ -41,6 +41,8 @@ void UpdateLog::Init(NS_tchar* sourcePath,
       // updater process if the elevated updater process has written the log.
       DeleteFileW(mDstFilePath);
     }
+#elif XP_MACOSX
+    logFP = NS_tfopen(mDstFilePath, NS_T("w"));
 #else
     // On platforms that have an updates directory in the installation directory
     // (e.g. platforms other than Windows and Mac) the update log is written to
@@ -59,7 +61,7 @@ void UpdateLog::Finish()
     return;
   }
 
-#if !defined(XP_WIN)
+#if !defined(XP_WIN) && !defined(XP_MACOSX)
   const int blockSize = 1024;
   char buffer[blockSize];
   fflush(logFP);
diff --git a/toolkit/mozapps/update/common/updatedefines.h b/toolkit/mozapps/update/common/updatedefines.h
index 0db182219a..49fbde6f2f 100644
--- a/toolkit/mozapps/update/common/updatedefines.h
+++ b/toolkit/mozapps/update/common/updatedefines.h
@@ -100,6 +100,10 @@ static inline int mywcsprintf(WCHAR* dest, size_t count, const WCHAR* fmt, ...)
 #endif
 # include <dirent.h>
 
+#ifdef XP_MACOSX
+# include <sys/time.h>
+#endif
+
 # define LOG_S "%s"
 # define NS_T(str) str
 # define NS_SLASH NS_T('/')
diff --git a/toolkit/mozapps/update/nsUpdateService.js b/toolkit/mozapps/update/nsUpdateService.js
index 9bea453dbb..ce9be2c512 100644
--- a/toolkit/mozapps/update/nsUpdateService.js
+++ b/toolkit/mozapps/update/nsUpdateService.js
@@ -315,6 +315,36 @@ function areDirectoryEntriesWriteable(aDir) {
 }
 
 /**
+ * OSX only function to determine if the user requires elevation to be able to
+ * write to the application bundle.
+ *
+ * @return true if elevation is required, false otherwise
+ */
+function getElevationRequired() {
+#ifdef XP_MACOSX
+  try {
+    // Recursively check that the application bundle (and its descendants) can
+    // be written to.
+    LOG("getElevationRequired - recursively testing write access on " +
+        getInstallDirRoot().path);
+    if (!getInstallDirRoot().isWritable() ||
+        !areDirectoryEntriesWriteable(getInstallDirRoot())) {
+      LOG("getElevationRequired - unable to write to application bundle, " +
+          "elevation required");
+      return true;
+    }
+  } catch (ex) {
+    LOG("getElevationRequired - unable to write to application bundle, " +
+        "elevation required. Exception: " + ex);
+    return true;
+  }
+  LOG("getElevationRequired - able to write to application bundle, elevation " +
+      "not required");
+#endif
+  return false;
+}
+
+/**
  * Determines whether or not an update can be applied. This is always true on
  * Windows when the service is used. Also, this is always true on OSX because we
  * offer users the option to perform an elevated update when necessary.
@@ -322,6 +352,7 @@ function areDirectoryEntriesWriteable(aDir) {
  * @return true if an update can be applied, false otherwise
  */
 function getCanApplyUpdates() {
+#ifndef XP_MACOSX
   try {
     let updateTestFile = getUpdateFile([FILE_UPDATE_TEST]);
     LOG("getCanApplyUpdates - testing write access " + updateTestFile.path);
@@ -400,6 +431,7 @@ function getCanApplyUpdates() {
     // No write privileges to install directory
     return false;
   }
+#endif // !XP_MACOSX
 
   LOG("getCanApplyUpdates - able to apply updates");
   return true;
@@ -412,17 +444,28 @@ function getCanApplyUpdates() {
  * @return true if updates can be staged for this session.
  */
 XPCOMUtils.defineLazyGetter(this, "gCanStageUpdatesSession", function aus_gCSUS() {
+  if (getElevationRequired()) {
+    LOG("gCanStageUpdatesSession - unable to stage updates because elevation " +
+        "is required.");
+    return false;
+  }
+
   try {
     let updateTestFile;
+#ifdef XP_MACOSX
+    updateTestFile = getUpdateFile([FILE_UPDATE_TEST]);
+#else
     updateTestFile = getInstallDirRoot();
     updateTestFile.append(FILE_UPDATE_TEST);
+#endif
 
     LOG("gCanStageUpdatesSession - testing write access " +
         updateTestFile.path);
     testWriteAccess(updateTestFile, true);
 
-    // On all platforms, we need to test the parent directory as well,
-    // as we need to be able to move files in that directory during the
+#ifndef XP_MACOSX
+    // On all platforms except Mac, we need to test the parent directory as
+    // well, as we need to be able to move files in that directory during the
     // replacing step.
     updateTestFile = getInstallDirRoot().parent;
     updateTestFile.append(FILE_UPDATE_TEST);
@@ -431,6 +474,7 @@ XPCOMUtils.defineLazyGetter(this, "gCanStageUpdatesSession", function aus_gCSUS(
     updateTestFile.createUnique(Ci.nsILocalFile.DIRECTORY_TYPE,
                                 FileUtils.PERMS_DIRECTORY);
     updateTestFile.remove(false);
+#endif // !XP_MACOSX
   } catch (e) {
     LOG("gCanStageUpdatesSession - unable to stage updates. Exception: " +
         e);
@@ -549,6 +593,10 @@ function getAppBaseDir() {
  */
 function getInstallDirRoot() {
   let dir = getAppBaseDir();
+#ifdef XP_MACOSX
+  // On Mac, we store the Updated.app directory inside the bundle directory.
+  dir = dir.parent.parent;
+#endif
   return dir;
 }
 
@@ -832,7 +880,31 @@ function handleUpdateFailure(update, errorCode) {
     cancelations++;
     Services.prefs.setIntPref(PREF_APP_UPDATE_CANCELATIONS, cancelations);
 
+#ifdef XP_MACOSX
+    let osxCancelations = Services.prefs.getIntPref(PREF_APP_UPDATE_CANCELATIONS_OSX, 0);
+    osxCancelations++;
+    Services.prefs.setIntPref(PREF_APP_UPDATE_CANCELATIONS_OSX,
+                              osxCancelations);
+    let maxCancels = Services.prefs.getIntPref(
+                             PREF_APP_UPDATE_CANCELATIONS_OSX_MAX,
+                             DEFAULT_CANCELATIONS_OSX_MAX);
+    // Prevent the preference from setting a value greater than 5.
+    maxCancels = Math.min(maxCancels, 5);
+    if (osxCancelations >= maxCancels) {
+      cleanupActiveUpdate();
+    } else {
+      writeStatusFile(getUpdatesDir(),
+                      update.state = STATE_PENDING_ELEVATE);
+    }
+    update.statusText = gUpdateBundle.GetStringFromName("elevationFailure");
+    update.QueryInterface(Ci.nsIWritablePropertyBag);
+    update.setProperty("patchingFailed", "elevationFailure");
+    let prompter = Cc["@mozilla.org/updates/update-prompt;1"].
+               createInstance(Ci.nsIUpdatePrompt);
+    prompter.showUpdateError(update);
+#else
     writeStatusFile(getUpdatesDir(), update.state = STATE_PENDING);
+#endif
 
     return true;
   }
@@ -1778,6 +1850,58 @@ UpdateService.prototype = {
     });
 
     let update = minorUpdate || majorUpdate;
+#ifdef XP_MACOSX
+    if (update) {
+      if (getElevationRequired()) {
+        let installAttemptVersion = Services.prefs.getCharPref(
+                                            PREF_APP_UPDATE_ELEVATE_VERSION,
+                                            "");
+        if (vc.compare(installAttemptVersion, update.appVersion) != 0) {
+          Services.prefs.setCharPref(PREF_APP_UPDATE_ELEVATE_VERSION,
+                                     update.appVersion);
+          if (Services.prefs.prefHasUserValue(
+                PREF_APP_UPDATE_CANCELATIONS_OSX)) {
+            Services.prefs.clearUserPref(PREF_APP_UPDATE_CANCELATIONS_OSX);
+          }
+          if (Services.prefs.prefHasUserValue(PREF_APP_UPDATE_ELEVATE_NEVER)) {
+            Services.prefs.clearUserPref(PREF_APP_UPDATE_ELEVATE_NEVER);
+          }
+        } else {
+          let numCancels = Services.prefs.getIntPref(PREF_APP_UPDATE_CANCELATIONS_OSX, 0);
+          let rejectedVersion = Services.prefs.getCharPref(PREF_APP_UPDATE_ELEVATE_NEVER, "");
+          let maxCancels = Services.prefs.getIntPref(PREF_APP_UPDATE_CANCELATIONS_OSX_MAX,
+                                   DEFAULT_CANCELATIONS_OSX_MAX);
+          if (numCancels >= maxCancels) {
+            LOG("UpdateService:selectUpdate - the user requires elevation to " +
+                "install this update, but the user has exceeded the max " +
+                "number of elevation attempts.");
+            update.elevationFailure = true;
+          } else if (vc.compare(rejectedVersion, update.appVersion) == 0) {
+            LOG("UpdateService:selectUpdate - the user requires elevation to " +
+                "install this update, but elevation is disabled for this " +
+                "version.");
+            update.elevationFailure = true;
+          } else {
+            LOG("UpdateService:selectUpdate - the user requires elevation to " +
+                "install the update.");
+          }
+        }
+      } else {
+        // Clear elevation-related prefs since they no longer apply (the user
+        // may have gained write access to the Firefox directory or an update
+        // was executed with a different profile).
+        if (Services.prefs.prefHasUserValue(PREF_APP_UPDATE_ELEVATE_VERSION)) {
+          Services.prefs.clearUserPref(PREF_APP_UPDATE_ELEVATE_VERSION);
+        }
+        if (Services.prefs.prefHasUserValue(PREF_APP_UPDATE_CANCELATIONS_OSX)) {
+          Services.prefs.clearUserPref(PREF_APP_UPDATE_CANCELATIONS_OSX);
+        }
+        if (Services.prefs.prefHasUserValue(PREF_APP_UPDATE_ELEVATE_NEVER)) {
+          Services.prefs.clearUserPref(PREF_APP_UPDATE_ELEVATE_NEVER);
+        }
+      }
+    }
+#endif
 
     return update;
   },
@@ -1895,8 +2019,7 @@ UpdateService.prototype = {
    * See nsIUpdateService.idl
    */
   get elevationRequired() {
-    /** Mac Stub, but keeping this for now to not break the API **/
-    return false;
+    return getElevationRequired();
   },
 
   /**
@@ -3147,7 +3270,11 @@ Downloader.prototype = {
         "max fail: " + maxFail + ", " + "retryTimeout: " + retryTimeout);
     if (Components.isSuccessCode(status)) {
       if (this._verifyDownload()) {
-        state = STATE_PENDING;
+        if (getElevationRequired()) {
+          state = STATE_PENDING_ELEVATE;
+        } else {
+          state = STATE_PENDING;
+        }
         if (this.background) {
           shouldShowPrompt = !getCanStageUpdates();
         }
diff --git a/toolkit/mozapps/update/updater/progressui.h b/toolkit/mozapps/update/updater/progressui.h
index 6dc20e06bc..5462815dee 100644
--- a/toolkit/mozapps/update/updater/progressui.h
+++ b/toolkit/mozapps/update/updater/progressui.h
@@ -24,6 +24,9 @@ int InitProgressUI(int *argc, NS_tchar ***argv);
   // Called on the main thread at startup
   int ShowProgressUI(bool indeterminate = false, bool initUIStrings = true);
   int InitProgressUIStrings();
+#elif defined(XP_MACOSX)
+  // Called on the main thread at startup
+  int ShowProgressUI(bool indeterminate = false);
 #else
   // Called on the main thread at startup
   int ShowProgressUI();
diff --git a/toolkit/mozapps/update/updater/updater.cpp b/toolkit/mozapps/update/updater/updater.cpp
index 13d829243f..f5f71935dc 100644
--- a/toolkit/mozapps/update/updater/updater.cpp
+++ b/toolkit/mozapps/update/updater/updater.cpp
@@ -53,6 +53,9 @@
 #include <algorithm>
 
 #include "updatecommon.h"
+#ifdef XP_MACOSX
+#include "updaterfileutils_osx.h"
+#endif // XP_MACOSX
 
 #include "mozilla/Compiler.h"
 #include "mozilla/Types.h"
@@ -72,6 +75,23 @@
 #define PARENT_WAIT 10000
 #endif
 
+#if defined(XP_MACOSX)
+// These functions are defined in launchchild_osx.mm
+void CleanupElevatedMacUpdate(bool aFailureOccurred);
+bool IsOwnedByGroupAdmin(const char* aAppBundle);
+bool IsRecursivelyWritable(const char* aPath);
+void LaunchChild(int argc, const char** argv);
+void LaunchMacPostProcess(const char* aAppBundle);
+bool ObtainUpdaterArguments(int* argc, char*** argv);
+bool ServeElevatedUpdate(int argc, const char** argv);
+void SetGroupOwnershipAndPermissions(const char* aAppBundle);
+struct UpdateServerThreadArgs
+{
+  int argc;
+  const NS_tchar** argv;
+};
+#endif
+
 #ifndef _O_BINARY
 # define _O_BINARY 0
 #endif
@@ -86,13 +106,14 @@
 
 // We want to use execv to invoke the callback executable on platforms where
 // we were launched using execv.  See nsUpdateDriver.cpp.
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) && !defined(XP_MACOSX)
 #define USE_EXECV
 #endif
 
 # define MAYBE_USE_HARD_LINKS 0
 
-#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN)
+#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && \
+    !defined(XP_MACOSX)
 #include "nss.h"
 #include "prerror.h"
 #endif
@@ -1675,6 +1696,21 @@ PatchFile::Execute()
 
   AutoFile ofile(ensure_open(mFile.get(), shouldTruncate ? NS_T("wb+") : NS_T("rb+"),
                              ss.st_mode));
+#elif defined(XP_MACOSX)
+  AutoFile ofile(ensure_open(mFile.get(), NS_T("wb+"), ss.st_mode));
+  // Modified code from FileUtils.cpp
+  fstore_t store = {F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, header.dlen};
+  // Try to get a continous chunk of disk space
+  rv = fcntl(fileno((FILE *)ofile), F_PREALLOCATE, &store);
+  if (rv == -1) {
+    // OK, perhaps we are too fragmented, allocate non-continuous
+    store.fst_flags = F_ALLOCATEALL;
+    rv = fcntl(fileno((FILE *)ofile), F_PREALLOCATE, &store);
+  }
+
+  if (rv != -1) {
+    ftruncate(fileno((FILE *)ofile), header.dlen);
+  }
 #else
   AutoFile ofile(ensure_open(mFile.get(), NS_T("wb+"), ss.st_mode));
 #endif
@@ -2055,6 +2091,8 @@ LaunchCallbackApp(const NS_tchar *workingDir,
 
 #if defined(USE_EXECV)
   execv(argv[0], argv);
+#elif defined(XP_MACOSX)
+  LaunchChild(argc, (const char**)argv);
 #elif defined(XP_WIN)
   WinLaunchChild(argv[0], argc, argv, nullptr);
 #else
@@ -2170,15 +2208,19 @@ CopyInstallDirToDestDir()
   // These files should not be copied over to the updated app
 #ifdef XP_WIN
 #define SKIPLIST_COUNT 3
+#elif XP_MACOSX
+#define SKIPLIST_COUNT 0
 #else
 #define SKIPLIST_COUNT 2
 #endif
   copy_recursive_skiplist<SKIPLIST_COUNT> skiplist;
+#ifndef XP_MACOSX
   skiplist.append(0, gInstallDirPath, NS_T("updated"));
   skiplist.append(1, gInstallDirPath, NS_T("updates/0"));
 #ifdef XP_WIN
   skiplist.append(2, gInstallDirPath, NS_T("updated.update_in_progress.lock"));
 #endif
+#endif
 
   return ensure_copy_recursive(gInstallDirPath, gWorkingDirPath, skiplist);
 }
@@ -2197,7 +2239,11 @@ ProcessReplaceRequest()
   // 2. Move newDir to destDir.  In case of failure, revert step 1 and abort.
   // 3. Delete tmpDir (or defer it to the next reboot).
 
-#if XP_WIN
+#ifdef XP_MACOSX
+  NS_tchar destDir[MAXPATHLEN];
+  NS_tsnprintf(destDir, sizeof(destDir)/sizeof(destDir[0]),
+               NS_T("%s/Contents"), gInstallDirPath);
+#elif XP_WIN
   // Windows preserves the case of the file/directory names.  We use the
   // GetLongPathName API in order to get the correct case for the directory
   // name, so that if the user has used a different case when launching the
@@ -2217,8 +2263,13 @@ ProcessReplaceRequest()
 
   NS_tchar newDir[MAXPATHLEN];
   NS_tsnprintf(newDir, sizeof(newDir)/sizeof(newDir[0]),
+#ifdef XP_MACOSX
+               NS_T("%s/Contents"),
+               gWorkingDirPath);
+#else
                NS_T("%s.bak/updated"),
                gInstallDirPath);
+#endif
 
   // First try to remove the possibly existing temp directory, because if this
   // directory exists, we will fail to rename destDir.
@@ -2256,6 +2307,14 @@ ProcessReplaceRequest()
   LOG(("Begin moving newDir (" LOG_S ") to destDir (" LOG_S ")",
        newDir, destDir));
   rv = rename_file(newDir, destDir, true);
+#ifdef XP_MACOSX
+  if (rv) {
+    LOG(("Moving failed. Begin copying newDir (" LOG_S ") to destDir (" LOG_S ")",
+         newDir, destDir));
+    copy_recursive_skiplist<0> skiplist;
+    rv = ensure_copy_recursive(newDir, destDir, skiplist);
+  }
+#endif
   if (rv) {
     LOG(("Moving newDir to destDir failed, err: %d", rv));
     LOG(("Now, try to move tmpDir back to destDir"));
@@ -2269,7 +2328,7 @@ ProcessReplaceRequest()
     return rv;
   }
 
-#if !defined(XP_WIN)
+#if !defined(XP_WIN) && !defined(XP_MACOSX)
   // Platforms that have their updates directory in the installation directory
   // need to have the last-update.log and backup-update.log files moved from the
   // old installation directory to the new installation directory.
@@ -2303,6 +2362,15 @@ ProcessReplaceRequest()
 #endif
   }
 
+#ifdef XP_MACOSX
+  // On OS X, we we need to remove the staging directory after its Contents
+  // directory has been moved.
+  NS_tchar updatedAppDir[MAXPATHLEN];
+  NS_tsnprintf(updatedAppDir, sizeof(updatedAppDir)/sizeof(updatedAppDir[0]),
+               NS_T("%s/Updated.app"), gPatchDirPath);
+  ensure_remove_recursive(updatedAppDir);
+#endif
+
   gSucceeded = true;
 
   return 0;
@@ -2412,7 +2480,11 @@ UpdateThreadFunc(void *param)
         NS_tchar updateSettingsPath[MAX_TEXT_LEN];
         NS_tsnprintf(updateSettingsPath,
                      sizeof(updateSettingsPath) / sizeof(updateSettingsPath[0]),
+#ifdef XP_MACOSX
+                     NS_T("%s/Contents/Resources/update-settings.ini"),
+#else
                      NS_T("%s/update-settings.ini"),
+#endif
                      gWorkingDirPath);
         MARChannelStringTable MARStrings;
         if (ReadMARChannelIDs(updateSettingsPath, &MARStrings) != OK) {
@@ -2484,6 +2556,15 @@ UpdateThreadFunc(void *param)
     if (rv) {
       LOG(("failed: %d", rv));
     } else {
+#ifdef XP_MACOSX
+      // If the update was successful we need to update the timestamp on the
+      // top-level Mac OS X bundle directory so that Mac OS X's Launch Services
+      // picks up any major changes when the bundle is updated.
+      if (!sStagedUpdate && utimes(gInstallDirPath, nullptr) != 0) {
+        LOG(("Couldn't set access/modification time on application bundle."));
+      }
+#endif
+
       LOG(("succeeded"));
     }
     WriteStatusFile(rv);
@@ -2493,11 +2574,34 @@ UpdateThreadFunc(void *param)
   QuitProgressUI();
 }
 
+#ifdef XP_MACOSX
+static void
+ServeElevatedUpdateThreadFunc(void* param)
+{
+  UpdateServerThreadArgs* threadArgs = (UpdateServerThreadArgs*)param;
+  gSucceeded = ServeElevatedUpdate(threadArgs->argc, threadArgs->argv);
+  if (!gSucceeded) {
+    WriteStatusFile(ELEVATION_CANCELED);
+  }
+  QuitProgressUI();
+}
+
+void freeArguments(int argc, char** argv)
+{
+  for (int i = 0; i < argc; i++) {
+    free(argv[i]);
+  }
+  free(argv);
+}
+#endif
+
 int LaunchCallbackAndPostProcessApps(int argc, NS_tchar** argv,
                                      int callbackIndex
 #ifdef XP_WIN
                                      , const WCHAR* elevatedLockFilePath
                                      , HANDLE updateLockFileHandle
+#elif XP_MACOSX
+                                     , bool isElevated
 #endif
                                      )
 {
@@ -2509,11 +2613,19 @@ int LaunchCallbackAndPostProcessApps(int argc, NS_tchar** argv,
       }
     }
     EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 0);
+#elif XP_MACOSX
+    if (!isElevated) {
+      if (gSucceeded) {
+        LaunchMacPostProcess(gInstallDirPath);
+      }
 #endif
 
     LaunchCallbackApp(argv[5],
                       argc - callbackIndex,
                       argv + callbackIndex);
+#ifdef XP_MACOSX
+    } // if (!isElevated)
+#endif /* XP_MACOSX */
   }
   return 0;
 }
@@ -2525,7 +2637,20 @@ int NS_main(int argc, NS_tchar **argv)
   // argument prior to callbackIndex is the working directory.
   const int callbackIndex = 6;
 
-#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN)
+#ifdef XP_MACOSX
+  bool isElevated =
+    strstr(argv[0], "/Library/PrivilegedHelperTools/org.mozilla.updater") != 0;
+  if (isElevated) {
+    if (!ObtainUpdaterArguments(&argc, &argv)) {
+      // Won't actually get here because ObtainUpdaterArguments will terminate
+      // the current process on failure.
+      return 1;
+    }
+  }
+#endif
+
+#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && \
+    !defined(XP_MACOSX)
   // On Windows and Mac we rely on native APIs to do verifications so we don't
   // need to initialize NSS at all there.
   // Otherwise, minimize the amount of NSS we depend on by avoiding all the NSS
@@ -2538,7 +2663,13 @@ int NS_main(int argc, NS_tchar **argv)
   }
 #endif
 
-  InitProgressUI(&argc, &argv);
+#ifdef XP_MACOSX
+  if (!isElevated) {
+#endif
+    InitProgressUI(&argc, &argv);
+#ifdef XP_MACOSX
+  }
+#endif
 
   // To process an update the updater command line must at a minimum have the
   // directory path containing the updater.mar file to process as the first
@@ -2556,6 +2687,12 @@ int NS_main(int argc, NS_tchar **argv)
   // launched.
   if (argc < 4) {
     fprintf(stderr, "Usage: updater patch-dir install-dir apply-to-dir [wait-pid [callback-working-dir callback-path args...]]\n");
+#ifdef XP_MACOSX
+    if (isElevated) {
+      freeArguments(argc, argv);
+      CleanupElevatedMacUpdate(true);
+    }
+#endif
     return 1;
   }
 
@@ -2564,6 +2701,12 @@ int NS_main(int argc, NS_tchar **argv)
     // directory is invalid don't write the status file.
     fprintf(stderr, "The patch directory path is not valid for this "  \
             "application (" LOG_S ")\n", argv[1]);
+#ifdef XP_MACOSX
+    if (isElevated) {
+      freeArguments(argc, argv);
+      CleanupElevatedMacUpdate(true);
+    }
+#endif
     return 1;
   }
   // The directory containing the update information.
@@ -2573,6 +2716,12 @@ int NS_main(int argc, NS_tchar **argv)
     WriteStatusFile(INVALID_INSTALL_DIR_PATH_ERROR);
     fprintf(stderr, "The install directory path is not valid for this "  \
             "application (" LOG_S ")\n", argv[2]);
+#ifdef XP_MACOSX
+    if (isElevated) {
+      freeArguments(argc, argv);
+      CleanupElevatedMacUpdate(true);
+    }
+#endif
     return 1;
   }
   // The directory we're going to update to.
@@ -2635,6 +2784,12 @@ int NS_main(int argc, NS_tchar **argv)
     WriteStatusFile(INVALID_WORKING_DIR_PATH_ERROR);
     fprintf(stderr, "The working directory path is not valid for this "  \
             "application (" LOG_S ")\n", argv[3]);
+#ifdef XP_MACOSX
+    if (isElevated) {
+      freeArguments(argc, argv);
+      CleanupElevatedMacUpdate(true);
+    }
+#endif
     return 1;
   }
   // The directory we're going to update to.
@@ -2653,6 +2808,12 @@ int NS_main(int argc, NS_tchar **argv)
       WriteStatusFile(INVALID_CALLBACK_PATH_ERROR);
       fprintf(stderr, "The callback file path is not valid for this "  \
               "application (" LOG_S ")\n", argv[callbackIndex]);
+#ifdef XP_MACOSX
+      if (isElevated) {
+        freeArguments(argc, argv);
+        CleanupElevatedMacUpdate(true);
+      }
+#endif
       return 1;
     }
 
@@ -2663,10 +2824,37 @@ int NS_main(int argc, NS_tchar **argv)
       WriteStatusFile(INVALID_CALLBACK_DIR_ERROR);
       fprintf(stderr, "The callback file must be located in the "  \
               "installation directory (" LOG_S ")\n", argv[callbackIndex]);
+#ifdef XP_MACOSX
+      if (isElevated) {
+        freeArguments(argc, argv);
+        CleanupElevatedMacUpdate(true);
+      }
+#endif
       return 1;
     }
   }
 
+#ifdef XP_MACOSX
+  if (!isElevated && !IsRecursivelyWritable(argv[2])) {
+    // If the app directory isn't recursively writeable, an elevated update is
+    // required.
+    UpdateServerThreadArgs threadArgs;
+    threadArgs.argc = argc;
+    threadArgs.argv = const_cast<const NS_tchar**>(argv);
+
+    Thread t1;
+    if (t1.Run(ServeElevatedUpdateThreadFunc, &threadArgs) == 0) {
+      // Show an indeterminate progress bar while an elevated update is in
+      // progress.
+      ShowProgressUI(true);
+    }
+    t1.Join();
+
+    LaunchCallbackAndPostProcessApps(argc, argv, callbackIndex, false);
+    return gSucceeded ? 0 : 1;
+  }
+#endif
+
   if (EnvHasValue("MOZ_OS_UPDATE")) {
     sIsOSUpdate = true;
     putenv(const_cast<char*>("MOZ_OS_UPDATE="));
@@ -2676,6 +2864,12 @@ int NS_main(int argc, NS_tchar **argv)
 
   if (!WriteStatusFile("applying")) {
     LOG(("failed setting status to 'applying'"));
+#ifdef XP_MACOSX
+    if (isElevated) {
+      freeArguments(argc, argv);
+      CleanupElevatedMacUpdate(true);
+    }
+#endif
     return 1;
   }
 
@@ -2912,6 +3106,12 @@ int NS_main(int argc, NS_tchar **argv)
     // Try to create the destination directory if it doesn't exist
     int rv = NS_tmkdir(gWorkingDirPath, 0755);
     if (rv != OK && errno != EEXIST) {
+#ifdef XP_MACOSX
+      if (isElevated) {
+        freeArguments(argc, argv);
+        CleanupElevatedMacUpdate(true);
+      }
+#endif
       return 1;
     }
   }
@@ -3152,7 +3352,11 @@ int NS_main(int argc, NS_tchar **argv)
   // is an elevated process on OSX.
   Thread t;
   if (t.Run(UpdateThreadFunc, nullptr) == 0) {
-    if (!sStagedUpdate && !sReplaceRequest) {
+    if (!sStagedUpdate && !sReplaceRequest
+#ifdef XP_MACOSX
+        && !isElevated
+#endif
+       ) {
       ShowProgressUI();
     }
   }
@@ -3189,12 +3393,66 @@ int NS_main(int argc, NS_tchar **argv)
   }
 #endif /* XP_WIN */
 
+#ifdef XP_MACOSX
+  // When the update is successful remove the precomplete file in the root of
+  // the application bundle and move the distribution directory from
+  // Contents/MacOS to Contents/Resources and if both exist delete the
+  // directory under Contents/MacOS (see Bug 1068439).
+  if (gSucceeded && !sStagedUpdate) {
+    NS_tchar oldPrecomplete[MAXPATHLEN];
+    NS_tsnprintf(oldPrecomplete, sizeof(oldPrecomplete)/sizeof(oldPrecomplete[0]),
+                 NS_T("%s/precomplete"), gInstallDirPath);
+    NS_tremove(oldPrecomplete);
+
+    NS_tchar oldDistDir[MAXPATHLEN];
+    NS_tsnprintf(oldDistDir, sizeof(oldDistDir)/sizeof(oldDistDir[0]),
+                 NS_T("%s/Contents/MacOS/distribution"), gInstallDirPath);
+    int rv = NS_taccess(oldDistDir, F_OK);
+    if (!rv) {
+      NS_tchar newDistDir[MAXPATHLEN];
+      NS_tsnprintf(newDistDir, sizeof(newDistDir)/sizeof(newDistDir[0]),
+                   NS_T("%s/Contents/Resources/distribution"), gInstallDirPath);
+      rv = NS_taccess(newDistDir, F_OK);
+      if (!rv) {
+        LOG(("New distribution directory already exists... removing old " \
+             "distribution directory: " LOG_S, oldDistDir));
+        rv = ensure_remove_recursive(oldDistDir);
+        if (rv) {
+          LOG(("Removing old distribution directory failed - err: %d", rv));
+        }
+      } else {
+        LOG(("Moving old distribution directory to new location. src: " LOG_S \
+             ", dst:" LOG_S, oldDistDir, newDistDir));
+        rv = rename_file(oldDistDir, newDistDir, true);
+        if (rv) {
+          LOG(("Moving old distribution directory to new location failed - " \
+               "err: %d", rv));
+        }
+      }
+    }
+  }
+
+  if (isElevated) {
+    SetGroupOwnershipAndPermissions(gInstallDirPath);
+    freeArguments(argc, argv);
+    CleanupElevatedMacUpdate(false);
+  } else if (IsOwnedByGroupAdmin(gInstallDirPath)) {
+    // If the group ownership of the Firefox .app bundle was set to the "admin"
+    // group during a previous elevated update, we need to ensure that all files
+    // in the bundle have group ownership of "admin" as well as write permission
+    // for the group to not break updates in the future.
+    SetGroupOwnershipAndPermissions(gInstallDirPath);
+  }
+#endif /* XP_MACOSX */
+
   LogFinish();
 
   int retVal = LaunchCallbackAndPostProcessApps(argc, argv, callbackIndex
 #ifdef XP_WIN
                                                 , elevatedLockFilePath
                                                 , updateLockFileHandle
+#elif XP_MACOSX
+                                                , isElevated
 #endif
                                                );
 
@@ -3650,8 +3908,13 @@ int AddPreCompleteActions(ActionList *list)
     return OK;
   }
 
+#ifdef XP_MACOSX
+  mozilla::UniquePtr<NS_tchar[]> manifestPath(get_full_path(
+    NS_T("Contents/Resources/precomplete")));
+#else
   mozilla::UniquePtr<NS_tchar[]> manifestPath(get_full_path(
     NS_T("precomplete")));
+#endif
 
   NS_tchar *rb = GetManifestContents(manifestPath.get());
   if (rb == nullptr) {
diff --git a/toolkit/profile/content/createProfileWizard.js b/toolkit/profile/content/createProfileWizard.js
index f378f36769..aa87eacd71 100644
--- a/toolkit/profile/content/createProfileWizard.js
+++ b/toolkit/profile/content/createProfileWizard.js
@@ -116,7 +116,11 @@ function checkCurrentInput(currentInput)
 
   if (!errorMessage) {
     finishText.className = "";
+#ifdef XP_MACOSX
+    finishText.firstChild.data = gProfileManagerBundle.getString("profileFinishTextMac");
+#else
     finishText.firstChild.data = gProfileManagerBundle.getString("profileFinishText");
+#endif
     canAdvance = true;
   }
   else {
diff --git a/toolkit/profile/content/createProfileWizard.xul b/toolkit/profile/content/createProfileWizard.xul
index c7e0702a62..eab1a93414 100644
--- a/toolkit/profile/content/createProfileWizard.xul
+++ b/toolkit/profile/content/createProfileWizard.xul
@@ -31,11 +31,15 @@
     <description>&profileCreationExplanation_2.text;</description>
     <description>&profileCreationExplanation_3.text;</description>
     <spacer flex="1"/>
+#ifdef XP_MACOSX
+    <description>&profileCreationExplanation_4Mac.text;</description>
+#else
 #ifdef XP_UNIX
     <description>&profileCreationExplanation_4Gnome.text;</description>
 #else
     <description>&profileCreationExplanation_4.text;</description>
 #endif
+#endif
   </wizardpage>
 
   <wizardpage id="createProfile" onpageshow="initSecondWizardPage();">
diff --git a/toolkit/profile/content/profileSelection.js b/toolkit/profile/content/profileSelection.js
index 9fb77dfcd0..05ef6f5edb 100644
--- a/toolkit/profile/content/profileSelection.js
+++ b/toolkit/profile/content/profileSelection.js
@@ -134,7 +134,9 @@ function onProfilesKey(aEvent)
   switch ( aEvent.keyCode )
   {
   case KeyEvent.DOM_VK_BACK_SPACE:
+#ifndef XP_MACOSX
     break;
+#endif
   case KeyEvent.DOM_VK_DELETE:
     ConfirmDelete();
     break;
diff --git a/toolkit/profile/jar.mn b/toolkit/profile/jar.mn
index 9b7c22266e..1c4afac4ca 100644
--- a/toolkit/profile/jar.mn
+++ b/toolkit/profile/jar.mn
@@ -3,7 +3,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 toolkit.jar:
-  content/mozapps/profile/createProfileWizard.js  (content/createProfileWizard.js)
+* content/mozapps/profile/createProfileWizard.js  (content/createProfileWizard.js)
 * content/mozapps/profile/createProfileWizard.xul (content/createProfileWizard.xul)
-  content/mozapps/profile/profileSelection.js     (content/profileSelection.js)
+* content/mozapps/profile/profileSelection.js     (content/profileSelection.js)
   content/mozapps/profile/profileSelection.xul    (content/profileSelection.xul)
diff --git a/toolkit/profile/nsProfileLock.cpp b/toolkit/profile/nsProfileLock.cpp
index 654fbcd465..d75b6082d3 100644
--- a/toolkit/profile/nsProfileLock.cpp
+++ b/toolkit/profile/nsProfileLock.cpp
@@ -13,6 +13,11 @@
 #include "nsAutoPtr.h"
 #endif
 
+#if defined(XP_MACOSX)
+#include <Carbon/Carbon.h>
+#include <CoreFoundation/CoreFoundation.h>
+#endif
+
 #ifdef XP_UNIX
 #include <unistd.h>
 #include <fcntl.h>
@@ -421,7 +426,10 @@ nsresult nsProfileLock::GetReplacedLockTime(PRTime *aResult) {
 nsresult nsProfileLock::Lock(nsIFile* aProfileDir,
                              nsIProfileUnlocker* *aUnlocker)
 {
-#if defined (XP_UNIX)
+#if defined (XP_MACOSX)
+    NS_NAMED_LITERAL_STRING(LOCKFILE_NAME, ".parentlock");
+    NS_NAMED_LITERAL_STRING(OLD_LOCKFILE_NAME, "parent.lock");
+#elif defined (XP_UNIX)
     NS_NAMED_LITERAL_STRING(OLD_LOCKFILE_NAME, "lock");
     NS_NAMED_LITERAL_STRING(LOCKFILE_NAME, ".parentlock");
 #else
@@ -450,7 +458,67 @@ nsresult nsProfileLock::Lock(nsIFile* aProfileDir,
     if (NS_FAILED(rv))
         return rv;
 
-#if defined(XP_UNIX)
+#if defined(XP_MACOSX)
+    // First, try locking using fcntl. It is more reliable on
+    // a local machine, but may not be supported by an NFS server.
+
+    rv = LockWithFcntl(lockFile);
+    if (NS_FAILED(rv) && (rv != NS_ERROR_FILE_ACCESS_DENIED))
+    {
+        // If that failed for any reason other than NS_ERROR_FILE_ACCESS_DENIED,
+        // assume we tried an NFS that does not support it. Now, try with symlink.
+        rv = LockWithSymlink(lockFile, false);
+    }
+
+    if (NS_SUCCEEDED(rv))
+    {
+        // Check for the old-style lock used by pre-mozilla 1.3 builds.
+        // Those builds used an earlier check to prevent the application
+        // from launching if another instance was already running. Because
+        // of that, we don't need to create an old-style lock as well.
+        struct LockProcessInfo
+        {
+            ProcessSerialNumber psn;
+            unsigned long launchDate;
+        };
+
+        PRFileDesc *fd = nullptr;
+        int32_t ioBytes;
+        ProcessInfoRec processInfo;
+        LockProcessInfo lockProcessInfo;
+
+        rv = lockFile->SetLeafName(OLD_LOCKFILE_NAME);
+        if (NS_FAILED(rv))
+            return rv;
+        rv = lockFile->OpenNSPRFileDesc(PR_RDONLY, 0, &fd);
+        if (NS_SUCCEEDED(rv))
+        {
+            ioBytes = PR_Read(fd, &lockProcessInfo, sizeof(LockProcessInfo));
+            PR_Close(fd);
+
+            if (ioBytes == sizeof(LockProcessInfo))
+            {
+#ifdef __LP64__
+                processInfo.processAppRef = nullptr;
+#else
+                processInfo.processAppSpec = nullptr;
+#endif
+                processInfo.processName = nullptr;
+                processInfo.processInfoLength = sizeof(ProcessInfoRec);
+                if (::GetProcessInformation(&lockProcessInfo.psn, &processInfo) == noErr &&
+                    processInfo.processLaunchDate == lockProcessInfo.launchDate)
+                {
+                    return NS_ERROR_FILE_ACCESS_DENIED;
+                }
+            }
+            else
+            {
+                NS_WARNING("Could not read lock file - ignoring lock");
+            }
+        }
+        rv = NS_OK; // Don't propagate error from OpenNSPRFileDesc.
+    }
+#elif defined(XP_UNIX)
     // Get the old lockfile name
     nsCOMPtr<nsIFile> oldLockFile;
     rv = aProfileDir->Clone(getter_AddRefs(oldLockFile));
diff --git a/toolkit/profile/nsToolkitProfileService.cpp b/toolkit/profile/nsToolkitProfileService.cpp
index 3380246da1..2fe51b2853 100644
--- a/toolkit/profile/nsToolkitProfileService.cpp
+++ b/toolkit/profile/nsToolkitProfileService.cpp
@@ -26,6 +26,11 @@
 #include "nsIFile.h"
 #include "nsISimpleEnumerator.h"
 
+#ifdef XP_MACOSX
+#include <CoreFoundation/CoreFoundation.h>
+#include "nsILocalFileMac.h"
+#endif
+
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsXULAppAPI.h"
 
@@ -1020,7 +1025,33 @@ NS_NewToolkitProfileService(nsIToolkitProfileService* *aResult)
 nsresult
 XRE_GetFileFromPath(const char *aPath, nsIFile* *aResult)
 {
-#if defined(XP_UNIX)
+#if defined(XP_MACOSX)
+    int32_t pathLen = strlen(aPath);
+    if (pathLen > MAXPATHLEN)
+        return NS_ERROR_INVALID_ARG;
+
+    CFURLRef fullPath =
+        CFURLCreateFromFileSystemRepresentation(nullptr, (const UInt8 *) aPath,
+                                                pathLen, true);
+    if (!fullPath)
+        return NS_ERROR_FAILURE;
+
+    nsCOMPtr<nsIFile> lf;
+    nsresult rv = NS_NewNativeLocalFile(EmptyCString(), true,
+                                        getter_AddRefs(lf));
+    if (NS_SUCCEEDED(rv)) {
+        nsCOMPtr<nsILocalFileMac> lfMac = do_QueryInterface(lf, &rv);
+        if (NS_SUCCEEDED(rv)) {
+            rv = lfMac->InitWithCFURL(fullPath);
+            if (NS_SUCCEEDED(rv)) {
+                lf.forget(aResult);
+            }
+        }
+    }
+    CFRelease(fullPath);
+    return rv;
+
+#elif defined(XP_UNIX)
     char fullPath[MAXPATHLEN];
 
     if (!realpath(aPath, fullPath))
diff --git a/toolkit/themes/shared/aboutReader.css b/toolkit/themes/shared/aboutReader.css
index c6cd959277..1bfbd0309d 100644
--- a/toolkit/themes/shared/aboutReader.css
+++ b/toolkit/themes/shared/aboutReader.css
@@ -388,7 +388,19 @@ body:not(.loaded) .toolbar:-moz-locale-dir(rtl) {
 }
 
 /* Font sizes are different per-platform, so we need custom CSS to line them up. */
-%ifdef XP_WIN
+%ifdef XP_MACOSX
+.font-type-buttons > .sans-serif-button > .name {
+  margin-top: 10px;
+}
+
+.font-type-buttons > .sans-serif-button > .description {
+  margin-top: -4px;
+}
+
+.font-type-buttons > .serif-button > .name {
+  font-size: 63px;
+}
+%elifdef XP_WIN
 .font-type-buttons > .sans-serif-button > .name {
   margin-top: 2px;
 }
diff --git a/toolkit/themes/shared/jar.inc.mn b/toolkit/themes/shared/jar.inc.mn
index 08f3250dcc..3755688279 100644
--- a/toolkit/themes/shared/jar.inc.mn
+++ b/toolkit/themes/shared/jar.inc.mn
@@ -62,7 +62,7 @@ toolkit.jar:
   skin/classic/global/media/TopLevelVideoDocument.css      (../../shared/media/TopLevelVideoDocument.css)
   skin/classic/global/media/imagedoc-lightnoise.png        (../../shared/media/imagedoc-lightnoise.png)
   skin/classic/global/media/imagedoc-darknoise.png         (../../shared/media/imagedoc-darknoise.png)
-  skin/classic/global/media/videocontrols.css              (../../shared/media/videocontrols.css)
+* skin/classic/global/media/videocontrols.css              (../../shared/media/videocontrols.css)
   skin/classic/global/media/pauseButton.png                (../../shared/media/pauseButton.png)
   skin/classic/global/media/pauseButton@2x.png             (../../shared/media/pauseButton@2x.png)
   skin/classic/global/media/playButton.png                 (../../shared/media/playButton.png)
diff --git a/toolkit/themes/shared/media/videocontrols.css b/toolkit/themes/shared/media/videocontrols.css
index 690762062b..a40d77fe3a 100644
--- a/toolkit/themes/shared/media/videocontrols.css
+++ b/toolkit/themes/shared/media/videocontrols.css
@@ -165,9 +165,15 @@
   font-size: 11px;
 }
 
+%ifdef XP_MACOSX
+.durationLabel {
+  padding-top: 2px; /* center vertically with scrubber bar */
+}
+%else
 .durationLabel {
   padding-top: 0; /* center vertically with scrubber bar */
 }
+%endif
 
 .positionLabel {
   display: none;
@@ -253,9 +259,15 @@
   padding-top: 7px;
 }
 
+%ifdef XP_MACOSX
+.timeLabel {
+  padding-top: 7px; /* center vertically with scrubber bar */
+}
+%else
 .timeLabel {
   padding-top: 5px; /* center vertically with scrubber bar */
 }
+%endif
 
 .statusOverlay {
   -moz-box-align: center;
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index b15335ade3..274631aac8 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -31,6 +31,16 @@
 #include "EventTracer.h"
 #endif
 
+#ifdef XP_MACOSX
+#include "nsVersionComparator.h"
+#include "MacLaunchHelper.h"
+#include "MacApplicationDelegate.h"
+#include "MacAutoreleasePool.h"
+// these are needed for sysctl
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#endif
+
 #include "prmem.h"
 #include "prnetdb.h"
 #include "prprf.h"
@@ -144,6 +154,11 @@
 #include "WinUtils.h"
 #endif
 
+#ifdef XP_MACOSX
+#include "nsILocalFileMac.h"
+#include "nsCommandLineServiceMac.h"
+#endif
+
 // for X remote support
 #ifdef MOZ_ENABLE_XREMOTE
 #include "XRemoteClient.h"
@@ -159,6 +174,10 @@
 #include <malloc.h>
 #endif
 
+#if defined (XP_MACOSX)
+#include <Carbon/Carbon.h>
+#endif
+
 #ifdef DEBUG
 #include "mozilla/Logging.h"
 #endif
@@ -1072,6 +1091,12 @@ ScopedXPCOMStartup::~ScopedXPCOMStartup()
   NS_IF_RELEASE(gNativeAppSupport);
 
   if (mServiceManager) {
+#ifdef XP_MACOSX
+    // On OS X, we need a pool to catch cocoa objects that are autoreleased
+    // during teardown.
+    mozilla::MacAutoreleasePool pool;
+#endif
+
     nsCOMPtr<nsIAppStartup> appStartup (do_GetService(NS_APPSTARTUP_CONTRACTID));
     if (appStartup)
       appStartup->DestroyHiddenWindow();
@@ -1457,6 +1482,10 @@ static nsresult LaunchChild(nsINativeAppSupport* aNative,
 
   SaveToEnv("MOZ_LAUNCHED_CHILD=1");
 
+#if defined(XP_MACOSX)
+  CommandLineServiceMac::SetupMacCommandLine(gRestartArgc, gRestartArgv, true);
+  LaunchChildMac(gRestartArgc, gRestartArgv);
+#else
   nsCOMPtr<nsIFile> lf;
   nsresult rv = XRE_GetBinaryPath(gArgv[0], getter_AddRefs(lf));
   if (NS_FAILED(rv))
@@ -1491,6 +1520,7 @@ static nsresult LaunchChild(nsINativeAppSupport* aNative,
     return NS_ERROR_FAILURE;
 #endif // XP_UNIX
 #endif // WP_WIN
+#endif // WP_MACOSX
 
   return NS_ERROR_LAUNCHED_CHILD_PROCESS;
 }
@@ -1559,9 +1589,15 @@ ProfileLockedDialog(nsIFile* aProfileDir, nsIFile* aProfileLocalDir,
     const char16_t* params[] = {appName.get(), appName.get()};
 
     nsXPIDLString killMessage;
+#ifndef XP_MACOSX
     sb->FormatStringFromName(aUnlocker ? u"restartMessageUnlocker"
                                        : u"restartMessageNoUnlocker",
                              params, 2, getter_Copies(killMessage));
+#else
+    sb->FormatStringFromName(aUnlocker ? u"restartMessageUnlockerMac"
+                                       : u"restartMessageNoUnlockerMac",
+                             params, 2, getter_Copies(killMessage));
+#endif
 
     nsXPIDLString killTitle;
     sb->FormatStringFromName(u"restartTitle",
@@ -1705,6 +1741,10 @@ ShowProfileManager(nsIToolkitProfileService* aProfileSvc,
     rv = xpcom.SetWindowCreator(aNative);
     NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
 
+#ifdef XP_MACOSX
+    CommandLineServiceMac::SetupMacCommandLine(gRestartArgc, gRestartArgv, true);
+#endif
+
 #ifdef XP_WIN
     // we don't have to wait here because profile manager window will pump
     // and DDE message will be handled
@@ -2810,6 +2850,13 @@ XREMain::XRE_mainInit(bool* aExitFlag)
     if (NS_FAILED(rv))
       return 2;
 
+#ifdef XP_MACOSX
+    nsCOMPtr<nsIFile> parent;
+    greDir->GetParent(getter_AddRefs(parent));
+    greDir = parent.forget();
+    greDir->AppendNative(NS_LITERAL_CSTRING("Resources"));
+#endif
+
     greDir.forget(&mAppData->xreDirectory);
   }
 
@@ -2843,6 +2890,40 @@ XREMain::XRE_mainInit(bool* aExitFlag)
   if (NS_FAILED(rv))
     return 1;
 
+#ifdef XP_MACOSX
+  // Set up ability to respond to system (Apple) events. This must occur before
+  // ProcessUpdates to ensure that links clicked in external applications aren't
+  // lost when updates are pending.
+  SetupMacApplicationDelegate();
+
+  if (EnvHasValue("MOZ_LAUNCHED_CHILD")) {
+    // This is needed, on relaunch, to force the OS to use the "Cocoa Dock
+    // API".  Otherwise the call to ReceiveNextEvent() below will make it
+    // use the "Carbon Dock API".  For more info see bmo bug 377166.
+    EnsureUseCocoaDockAPI();
+
+    // When the app relaunches, the original process exits.  This causes
+    // the dock tile to stop bouncing, lose the "running" triangle, and
+    // if the tile does not permanently reside in the Dock, even disappear.
+    // This can be confusing to the user, who is expecting the app to launch.
+    // Calling ReceiveNextEvent without requesting any event is enough to
+    // cause a dock tile for the child process to appear.
+    const EventTypeSpec kFakeEventList[] = { { INT_MAX, INT_MAX } };
+    EventRef event;
+    ::ReceiveNextEvent(GetEventTypeCount(kFakeEventList), kFakeEventList,
+                       kEventDurationNoWait, false, &event);
+  }
+
+  if (CheckArg("foreground")) {
+    // The original process communicates that it was in the foreground by
+    // adding this argument.  This new process, which is taking over for
+    // the old one, should make itself the active application.
+    ProcessSerialNumber psn;
+    if (::GetCurrentProcess(&psn) == noErr)
+      ::SetFrontProcess(&psn);
+  }
+#endif
+
   SaveToEnv("MOZ_LAUNCHED_CHILD=");
 
   gRestartArgc = gArgc;
@@ -2893,6 +2974,12 @@ XREMain::XRE_mainInit(bool* aExitFlag)
   }
 #endif
 
+#ifdef XP_MACOSX
+  if ((GetCurrentEventKeyModifiers() & optionKey) &&
+      !EnvHasValue("MOZ_DISABLE_SAFE_MODE_KEY"))
+    gSafeMode = true;
+#endif
+
 #ifdef XP_WIN
   {
     // Add CPU microcode version to the crash report as "CPUMicrocodeVersion".
@@ -3666,6 +3753,19 @@ XREMain::XRE_mainRun()
     g_unsetenv ("DESKTOP_STARTUP_ID");
 #endif
 
+#ifdef XP_MACOSX
+    // we re-initialize the command-line service and do appleevents munging
+    // after we are sure that we're not restarting
+    cmdLine = do_CreateInstance("@mozilla.org/toolkit/command-line;1");
+    NS_ENSURE_TRUE(cmdLine, NS_ERROR_FAILURE);
+
+    CommandLineServiceMac::SetupMacCommandLine(gArgc, gArgv, false);
+
+    rv = cmdLine->Init(gArgc, gArgv,
+                        workingDir, nsICommandLine::STATE_INITIAL_LAUNCH);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+#endif
+
     nsCOMPtr<nsIObserverService> obsService =
       mozilla::services::GetObserverService();
     if (obsService)
diff --git a/toolkit/xre/nsEmbedFunctions.cpp b/toolkit/xre/nsEmbedFunctions.cpp
index 841ea2a2d0..109782b5f8 100644
--- a/toolkit/xre/nsEmbedFunctions.cpp
+++ b/toolkit/xre/nsEmbedFunctions.cpp
@@ -39,6 +39,10 @@
 #include "nsXREDirProvider.h"
 
 #include "mozilla/Omnijar.h"
+#if defined(XP_MACOSX)
+#include "nsVersionComparator.h"
+#include "chrome/common/mach_ipc_mac.h"
+#endif
 #include "nsX11ErrorHandler.h"
 #include "nsGDKErrorHandler.h"
 #include "base/at_exit.h"
@@ -280,6 +284,81 @@ XRE_InitChildProcess(int aArgc,
   PROFILER_LABEL("Startup", "XRE_InitChildProcess",
     js::ProfileEntry::Category::OTHER);
 
+  // Complete 'task_t' exchange for Mac OS X. This structure has the same size
+  // regardless of architecture so we don't have any cross-arch issues here.
+#ifdef XP_MACOSX
+  if (aArgc < 1)
+    return NS_ERROR_FAILURE;
+  const char* const mach_port_name = aArgv[--aArgc];
+
+  const int kTimeoutMs = 1000;
+
+  MachSendMessage child_message(0);
+  if (!child_message.AddDescriptor(MachMsgPortDescriptor(mach_task_self()))) {
+    NS_WARNING("child AddDescriptor(mach_task_self()) failed.");
+    return NS_ERROR_FAILURE;
+  }
+
+  ReceivePort child_recv_port;
+  mach_port_t raw_child_recv_port = child_recv_port.GetPort();
+  if (!child_message.AddDescriptor(MachMsgPortDescriptor(raw_child_recv_port))) {
+    NS_WARNING("Adding descriptor to message failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  ReceivePort* ports_out_receiver = new ReceivePort();
+  if (!child_message.AddDescriptor(MachMsgPortDescriptor(ports_out_receiver->GetPort()))) {
+    NS_WARNING("Adding descriptor to message failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  ReceivePort* ports_in_receiver = new ReceivePort();
+  if (!child_message.AddDescriptor(MachMsgPortDescriptor(ports_in_receiver->GetPort()))) {
+    NS_WARNING("Adding descriptor to message failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  MachPortSender child_sender(mach_port_name);
+  kern_return_t err = child_sender.SendMessage(child_message, kTimeoutMs);
+  if (err != KERN_SUCCESS) {
+    NS_WARNING("child SendMessage() failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  MachReceiveMessage parent_message;
+  err = child_recv_port.WaitForMessage(&parent_message, kTimeoutMs);
+  if (err != KERN_SUCCESS) {
+    NS_WARNING("child WaitForMessage() failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  if (parent_message.GetTranslatedPort(0) == MACH_PORT_NULL) {
+    NS_WARNING("child GetTranslatedPort(0) failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  err = task_set_bootstrap_port(mach_task_self(),
+                                parent_message.GetTranslatedPort(0));
+
+  if (parent_message.GetTranslatedPort(1) == MACH_PORT_NULL) {
+    NS_WARNING("child GetTranslatedPort(1) failed");
+    return NS_ERROR_FAILURE;
+  }
+  MachPortSender* ports_out_sender = new MachPortSender(parent_message.GetTranslatedPort(1));
+
+  if (parent_message.GetTranslatedPort(2) == MACH_PORT_NULL) {
+    NS_WARNING("child GetTranslatedPort(2) failed");
+    return NS_ERROR_FAILURE;
+  }
+  MachPortSender* ports_in_sender = new MachPortSender(parent_message.GetTranslatedPort(2));
+
+  if (err != KERN_SUCCESS) {
+    NS_WARNING("child task_set_bootstrap_port() failed");
+    return NS_ERROR_FAILURE;
+  }
+
+#endif
+
   SetupErrorHandling(aArgv[0]);  
 
   gArgv = aArgv;
@@ -325,6 +404,11 @@ XRE_InitChildProcess(int aArgc,
   base::ProcessId parentPID = strtol(parentPIDString, &end, 10);
   MOZ_ASSERT(!*end, "invalid parent PID");
 
+#ifdef XP_MACOSX
+  mozilla::ipc::SharedMemoryBasic::SetupMachMemory(parentPID, ports_in_receiver, ports_in_sender,
+                                                   ports_out_sender, ports_out_receiver, true);
+#endif
+
 #if defined(XP_WIN)
   // On Win7+, register the application user model id passed in by
   // parent. This insures windows created by the container properly
@@ -456,6 +540,11 @@ XRE_InitChildProcess(int aArgc,
       // scope and being deleted
       process->CleanUp();
       mozilla::Omnijar::CleanUp();
+
+#if defined(XP_MACOSX)
+      // Everybody should be done using shared memory by now.
+      mozilla::ipc::SharedMemoryBasic::Shutdown();
+#endif
     }
   }
 
@@ -571,6 +660,47 @@ XRE_RunAppShell()
 {
     nsCOMPtr<nsIAppShell> appShell(do_GetService(kAppShellCID));
     NS_ENSURE_TRUE(appShell, NS_ERROR_FAILURE);
+#if defined(XP_MACOSX)
+    {
+      // In content processes that want XPCOM (and hence want
+      // AppShell), we usually run our hybrid event loop through
+      // MessagePump::Run(), by way of nsBaseAppShell::Run().  The
+      // Cocoa nsAppShell impl, however, implements its own Run()
+      // that's unaware of MessagePump.  That's all rather suboptimal,
+      // but oddly enough not a problem... usually.
+      // 
+      // The problem with this setup comes during startup.
+      // XPCOM-in-subprocesses depends on IPC, e.g. to init the pref
+      // service, so we have to init IPC first.  But, IPC also
+      // indirectly kinda-depends on XPCOM, because MessagePump
+      // schedules work from off-main threads (e.g. IO thread) by
+      // using NS_DispatchToMainThread().  If the IO thread receives a
+      // Message from the parent before nsThreadManager is
+      // initialized, then DispatchToMainThread() will fail, although
+      // MessagePump will remember the task.  This race condition
+      // isn't a problem when appShell->Run() ends up in
+      // MessagePump::Run(), because MessagePump will immediate see it
+      // has work to do.  It *is* a problem when we end up in [NSApp
+      // run], because it's not aware that MessagePump has work that
+      // needs to be processed; that was supposed to be signaled by
+      // nsIRunnable(s).
+      // 
+      // So instead of hacking Cocoa nsAppShell or rewriting the
+      // event-loop system, we compromise here by processing any tasks
+      // that might have been enqueued on MessagePump, *before*
+      // MessagePump::ScheduleWork was able to successfully
+      // DispatchToMainThread().
+      MessageLoop* loop = MessageLoop::current();
+      bool couldNest = loop->NestableTasksAllowed();
+
+      loop->SetNestableTasksAllowed(true);
+      RefPtr<Runnable> task = new MessageLoop::QuitTask();
+      loop->PostTask(task.forget());
+      loop->Run();
+
+      loop->SetNestableTasksAllowed(couldNest);
+    }
+#endif  // XP_MACOSX
     return appShell->Run();
 }
 
@@ -589,6 +719,16 @@ XRE_ShutdownChildProcess()
   //  (4) ProcessChild joins the IO thread
   //  (5) exit()
   MessageLoop::current()->Quit();
+#if defined(XP_MACOSX)
+  nsCOMPtr<nsIAppShell> appShell(do_GetService(kAppShellCID));
+  if (appShell) {
+      // On Mac, we might be only above nsAppShell::Run(), not
+      // MessagePump::Run().  See XRE_RunAppShell(). To account for
+      // that case, we fire off an Exit() here.  If we were indeed
+      // above MessagePump::Run(), this Exit() is just superfluous.
+      appShell->Exit();
+  }
+#endif // XP_MACOSX
 }
 
 namespace {
diff --git a/toolkit/xre/nsSigHandlers.cpp b/toolkit/xre/nsSigHandlers.cpp
index 68d909848c..11648e45ac 100644
--- a/toolkit/xre/nsSigHandlers.cpp
+++ b/toolkit/xre/nsSigHandlers.cpp
@@ -154,6 +154,22 @@ static void fpehandler(int signum, siginfo_t *si, void *context)
     NS_DebugBreak(NS_DEBUG_ABORT, "Divide by zero", nullptr, __FILE__, __LINE__);
   }
 
+#ifdef XP_MACOSX
+  ucontext_t *uc = (ucontext_t *)context;
+
+#if defined(__i386__) || defined(__amd64__)
+  _STRUCT_FP_CONTROL *ctrl = &uc->uc_mcontext->__fs.__fpu_fcw;
+  ctrl->__invalid = ctrl->__denorm = ctrl->__zdiv = ctrl->__ovrfl = ctrl->__undfl = ctrl->__precis = 1;
+
+  _STRUCT_FP_STATUS *status = &uc->uc_mcontext->__fs.__fpu_fsw;
+  status->__invalid = status->__denorm = status->__zdiv = status->__ovrfl = status->__undfl =
+    status->__precis = status->__stkflt = status->__errsumm = 0;
+
+  uint32_t *mxcsr = &uc->uc_mcontext->__fs.__fpu_mxcsr;
+  *mxcsr |= SSE_EXCEPTION_MASK; /* disable all SSE exceptions */
+  *mxcsr &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
+#endif
+#endif
 #if defined(LINUX)
   ucontext_t *uc = (ucontext_t *)context;
 
diff --git a/toolkit/xre/nsUpdateDriver.cpp b/toolkit/xre/nsUpdateDriver.cpp
index 812818788c..4994458852 100644
--- a/toolkit/xre/nsUpdateDriver.cpp
+++ b/toolkit/xre/nsUpdateDriver.cpp
@@ -1,4 +1,5 @@
 /* -*- 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/. */
@@ -26,6 +27,13 @@
 #include "nsPrintfCString.h"
 #include "mozilla/DebugOnly.h"
 
+#ifdef XP_MACOSX
+#include "nsILocalFileMac.h"
+#include "nsCommandLineServiceMac.h"
+#include "MacLaunchHelper.h"
+#include "updaterfileutils_osx.h"
+#endif
+
 #if defined(XP_WIN)
 # include <direct.h>
 # include <process.h>
@@ -53,11 +61,16 @@ GetUpdateLog()
 
 #ifdef XP_WIN
 #define UPDATER_BIN "updater.exe"
+#elif XP_MACOSX
+#define UPDATER_BIN "org.mozilla.updater"
 #else
 #define UPDATER_BIN "updater"
 #endif
 #define UPDATER_INI "updater.ini"
-#if defined(XP_UNIX)
+#ifdef XP_MACOSX
+#define UPDATER_APP "updater.app"
+#endif
+#if defined(XP_UNIX) && !defined(XP_MACOSX)
 #define UPDATER_PNG "updater.png"
 #endif
 
@@ -96,7 +109,18 @@ static nsresult
 GetInstallDirPath(nsIFile *appDir, nsACString& installDirPath)
 {
   nsresult rv;
-#if XP_WIN
+#ifdef XP_MACOSX
+  nsCOMPtr<nsIFile> parentDir1, parentDir2;
+  rv = appDir->GetParent(getter_AddRefs(parentDir1));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = parentDir1->GetParent(getter_AddRefs(parentDir2));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = parentDir2->GetNativePath(installDirPath);
+#elif XP_WIN
   nsAutoString installDirPathW;
   rv = appDir->GetPath(installDirPathW);
   if (NS_FAILED(rv)) {
@@ -112,6 +136,35 @@ GetInstallDirPath(nsIFile *appDir, nsACString& installDirPath)
   return NS_OK;
 }
 
+#if defined(XP_MACOSX)
+// This is a copy of OS X's XRE_GetBinaryPath from nsAppRunner.cpp with the
+// gBinaryPath check removed so that the updater can reload the stub executable
+// instead of xulrunner-bin. See bug 349737.
+static nsresult
+GetXULRunnerStubPath(const char* argv0, nsIFile* *aResult)
+{
+  // Works even if we're not bundled.
+  CFBundleRef appBundle = ::CFBundleGetMainBundle();
+  if (!appBundle)
+    return NS_ERROR_FAILURE;
+
+  CFURLRef bundleURL = ::CFBundleCopyExecutableURL(appBundle);
+  if (!bundleURL)
+    return NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsILocalFileMac> lfm;
+  nsresult rv = NS_NewLocalFileWithCFURL(bundleURL, true, getter_AddRefs(lfm));
+
+  ::CFRelease(bundleURL);
+
+  if (NS_FAILED(rv))
+    return rv;
+
+  lfm.forget(aResult);
+  return NS_OK;
+}
+#endif /* XP_MACOSX */
+
 static bool
 GetFile(nsIFile *dir, const nsCSubstring &name, nsCOMPtr<nsIFile> &result)
 {
@@ -271,10 +324,16 @@ CopyUpdaterIntoUpdateDir(nsIFile *greDir, nsIFile *appDir, nsIFile *updateDir,
                          nsCOMPtr<nsIFile> &updater)
 {
   // Copy the updater application from the GRE and the updater ini from the app
+#if defined(XP_MACOSX)
+  if (!CopyFileIntoUpdateDir(appDir, NS_LITERAL_CSTRING(UPDATER_APP), updateDir))
+    return false;
+  CopyFileIntoUpdateDir(greDir, NS_LITERAL_CSTRING(UPDATER_INI), updateDir);
+#else
   if (!CopyFileIntoUpdateDir(greDir, NS_LITERAL_CSTRING(UPDATER_BIN), updateDir))
     return false;
   CopyFileIntoUpdateDir(appDir, NS_LITERAL_CSTRING(UPDATER_INI), updateDir);
-#if defined(XP_UNIX)
+#endif
+#if defined(XP_UNIX) && !defined(XP_MACOSX)
   nsCOMPtr<nsIFile> iconDir;
   appDir->Clone(getter_AddRefs(iconDir));
   iconDir->AppendNative(NS_LITERAL_CSTRING("icons"));
@@ -285,6 +344,16 @@ CopyUpdaterIntoUpdateDir(nsIFile *greDir, nsIFile *appDir, nsIFile *updateDir,
   nsresult rv = updateDir->Clone(getter_AddRefs(updater));
   if (NS_FAILED(rv))
     return false;
+#if defined(XP_MACOSX)
+  rv  = updater->AppendNative(NS_LITERAL_CSTRING(UPDATER_APP));
+  nsresult tmp = updater->AppendNative(NS_LITERAL_CSTRING("Contents"));
+  if (NS_FAILED(tmp)) {
+    rv = tmp;
+  }
+  tmp = updater->AppendNative(NS_LITERAL_CSTRING("MacOS"));
+  if (NS_FAILED(tmp) || NS_FAILED(rv))
+    return false;
+#endif
   rv = updater->AppendNative(NS_LITERAL_CSTRING(UPDATER_BIN));
   return NS_SUCCEEDED(rv);
 }
@@ -295,7 +364,8 @@ CopyUpdaterIntoUpdateDir(nsIFile *greDir, nsIFile *appDir, nsIFile *updateDir,
  *
  * @param pathToAppend A new library path to prepend to LD_LIBRARY_PATH
  */
-#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN)
+#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && \
+    !defined(XP_MACOSX)
 #include "prprf.h"
 #define PATH_SEPARATOR ":"
 #define LD_LIBRARY_PATH_ENVVAR_NAME "LD_LIBRARY_PATH"
@@ -372,7 +442,13 @@ SwitchToUpdatedApp(nsIFile *greDir, nsIFile *updateDir,
   // to restart the running application.
   nsCOMPtr<nsIFile> appFile;
 
+#if defined(XP_MACOSX)
+  // On OS X we need to pass the location of the xulrunner-stub executable
+  // rather than xulrunner-bin. See bug 349737.
+  GetXULRunnerStubPath(appArgv[0], getter_AddRefs(appFile));
+#else
   XRE_GetBinaryPath(appArgv[0], getter_AddRefs(appFile));
+#endif
 
   if (!appFile)
     return;
@@ -424,7 +500,11 @@ SwitchToUpdatedApp(nsIFile *greDir, nsIFile *updateDir,
   // Get the directory where the update will be staged.
   nsAutoCString applyToDir;
   nsCOMPtr<nsIFile> updatedDir;
+#ifdef XP_MACOSX
+  if (!GetFile(updateDir, NS_LITERAL_CSTRING("Updated.app"), updatedDir)) {
+#else
   if (!GetFile(appDir, NS_LITERAL_CSTRING("updated"), updatedDir)) {
+#endif
     return;
   }
 #ifdef XP_WIN
@@ -468,7 +548,7 @@ SwitchToUpdatedApp(nsIFile *greDir, nsIFile *updateDir,
   // Construct the PID argument for this process. We start the updater using
   // execv on all Unix platforms except Mac, so on those platforms we pass 0
   // instead of a good PID to signal the updater not to try and wait for us.
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) & !defined(XP_MACOSX)
   nsAutoCString pid("0");
 #else
   nsAutoCString pid;
@@ -508,13 +588,14 @@ SwitchToUpdatedApp(nsIFile *greDir, nsIFile *updateDir,
   if (gSafeMode) {
     PR_SetEnv("MOZ_SAFE_MODE_RESTART=1");
   }
-#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN)
+#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && \
+    !defined(XP_MACOSX)
   AppendToLibPath(installDirPath.get());
 #endif
 
   LOG(("spawning updater process for replacing [%s]\n", updaterPath.get()));
 
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) & !defined(XP_MACOSX)
   exit(execv(updaterPath.get(), argv));
 #elif defined(XP_WIN)
   // Switch the application using updater.exe
@@ -522,6 +603,10 @@ SwitchToUpdatedApp(nsIFile *greDir, nsIFile *updateDir,
     return;
   }
   _exit(0);
+#elif defined(XP_MACOSX)
+  CommandLineServiceMac::SetupMacCommandLine(argc, argv, true);
+  LaunchChildMac(argc, argv);
+  exit(0);
 #else
   PR_CreateProcessDetached(updaterPath.get(), argv, nullptr, nullptr);
   exit(0);
@@ -567,7 +652,13 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
   // to restart the running application.
   nsCOMPtr<nsIFile> appFile;
 
+#if defined(XP_MACOSX)
+  // On OS X we need to pass the location of the xulrunner-stub executable
+  // rather than xulrunner-bin. See bug 349737.
+  GetXULRunnerStubPath(appArgv[0], getter_AddRefs(appFile));
+#else
   XRE_GetBinaryPath(appArgv[0], getter_AddRefs(appFile));
+#endif
 
   if (!appFile)
     return;
@@ -623,7 +714,11 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
   if (restart && !isOSUpdate) {
     applyToDir.Assign(installDirPath);
   } else {
+#ifdef XP_MACOSX
+    if (!GetFile(updateDir, NS_LITERAL_CSTRING("Updated.app"), updatedDir)) {
+#else
     if (!GetFile(appDir, NS_LITERAL_CSTRING("updated"), updatedDir)) {
+#endif
       return;
     }
 #ifdef XP_WIN
@@ -678,7 +773,7 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
     // Signal the updater application that it should stage the update.
     pid.AssignASCII("-1");
   } else {
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) & !defined(XP_MACOSX)
     pid.AssignASCII("0");
 #else
     pid.AppendInt((int32_t) getpid());
@@ -714,7 +809,8 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
   if (gSafeMode) {
     PR_SetEnv("MOZ_SAFE_MODE_RESTART=1");
   }
-#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN)
+#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && \
+    !defined(XP_MACOSX)
   AppendToLibPath(installDirPath.get());
 #endif
 
@@ -724,10 +820,10 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
 
   LOG(("spawning updater process [%s]\n", updaterPath.get()));
 
-#if defined(XP_UNIX)
-  // We use execv to spawn the updater process on all UNIX-like systems.
-  // Windows has execv, but it is a faked implementation that doesn't really
-  // replace the current process.
+#if defined(XP_UNIX) && !defined(XP_MACOSX)
+  // We use execv to spawn the updater process on all UNIX systems except Mac OSX
+  // since it is known to cause problems on the Mac.  Windows has execv, but it
+  // is a faked implementation that doesn't really replace the current process.
   // Instead it spawns a new process, so we gain nothing from using execv on
   // Windows.
   if (restart) {
@@ -749,6 +845,24 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
     // We are going to process an update so we should exit now
     _exit(0);
   }
+#elif defined(XP_MACOSX)
+  CommandLineServiceMac::SetupMacCommandLine(argc, argv, restart);
+  // We need to detect whether elevation is required for this update. This can
+  // occur when an admin user installs the application, but another admin
+  // user attempts to update (see bug 394984).
+  if (restart && !IsRecursivelyWritable(installDirPath.get())) {
+    if (!LaunchElevatedUpdate(argc, argv, outpid)) {
+      LOG(("Failed to launch elevated update!"));
+      exit(1);
+    }
+    exit(0);
+  } else {
+    if (restart) {
+      LaunchChildMac(argc, argv);
+      exit(0);
+    }
+    LaunchChildMac(argc, argv, outpid);
+  }
 #else
   *outpid = PR_CreateProcess(updaterPath.get(), argv, nullptr, nullptr);
   if (restart) {
@@ -769,6 +883,9 @@ ProcessHasTerminated(ProcessType pt)
   }
   CloseHandle(pt);
   return true;
+#elif defined(XP_MACOSX)
+  // We're waiting for the process to terminate in LaunchChildMac.
+  return true;
 #elif defined(XP_UNIX)
   int exitStatus;
   pid_t exited = waitpid(pt, &exitStatus, WNOHANG);
diff --git a/toolkit/xre/nsXREDirProvider.cpp b/toolkit/xre/nsXREDirProvider.cpp
index fdeee8d0f9..e38cc4f35b 100644
--- a/toolkit/xre/nsXREDirProvider.cpp
+++ b/toolkit/xre/nsXREDirProvider.cpp
@@ -48,11 +48,19 @@
 #include <windows.h>
 #include <shlobj.h>
 #endif
+#ifdef XP_MACOSX
+#include "nsILocalFileMac.h"
+// for chflags()
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
 #ifdef XP_UNIX
 #include <ctype.h>
 #endif
 
-#if defined(XP_WIN)
+#if defined(XP_MACOSX)
+#define APP_REGISTRY_NAME "Application Registry"
+#elif defined(XP_WIN)
 #define APP_REGISTRY_NAME "registry.dat"
 #else
 #define APP_REGISTRY_NAME "appreg"
@@ -100,6 +108,9 @@ nsXREDirProvider::Initialize(nsIFile *aXULAppDir,
   mXULAppDir = aXULAppDir;
   mGREDir = aGREDir;
   mGREDir->Clone(getter_AddRefs(mGREBinDir));
+#ifdef XP_MACOSX
+  mGREBinDir->SetNativeLeafName(NS_LITERAL_CSTRING("MacOS"));
+#endif
 
   if (!mProfileDir) {
     nsCOMPtr<nsIDirectoryServiceProvider> app(do_QueryInterface(mAppProvider));
@@ -129,6 +140,30 @@ nsXREDirProvider::SetProfile(nsIFile* aDir, nsIFile* aLocalDir)
   if (NS_FAILED(rv))
     return rv;
 
+#ifdef XP_MACOSX
+  bool same;
+  if (NS_SUCCEEDED(aDir->Equals(aLocalDir, &same)) && !same) {
+    // Ensure that the cache directory is not indexed by Spotlight
+    // (bug 718910).  At least on OS X, the cache directory (under
+    // ~/Library/Caches/) is always the "local" user profile
+    // directory.  This is confusing, since *both* user profile
+    // directories are "local" (they both exist under the user's
+    // home directory).  But this usage dates back at least as far
+    // as the patch for bug 291033, where "local" seems to mean
+    // "suitable for temporary storage".  Don't hide the cache
+    // directory if by some chance it and the "non-local" profile
+    // directory are the same -- there are bad side effects from
+    // hiding a profile directory under /Library/Application Support/
+    // (see bug 801883).
+    nsAutoCString cacheDir;
+    if (NS_SUCCEEDED(aLocalDir->GetNativePath(cacheDir))) {
+      if (chflags(cacheDir.get(), UF_HIDDEN)) {
+        NS_WARNING("Failed to set Cache directory to HIDDEN.");
+      }
+    }
+  }
+#endif
+
   mProfileDir = aDir;
   mProfileLocalDir = aLocalDir;
   return NS_OK;
@@ -163,7 +198,7 @@ nsXREDirProvider::GetUserProfilesRootDir(nsIFile** aResult,
                                      aProfileName, aAppName, aVendorName);
 
   if (NS_SUCCEEDED(rv)) {
-#if !defined(XP_UNIX)
+#if !defined(XP_UNIX) || defined(XP_MACOSX)
     rv = file->AppendNative(NS_LITERAL_CSTRING("Profiles"));
 #endif
     // We must create the profile directory here if it does not exist.
@@ -188,7 +223,7 @@ nsXREDirProvider::GetUserProfilesLocalDir(nsIFile** aResult,
                                      aProfileName, aAppName, aVendorName);
 
   if (NS_SUCCEEDED(rv)) {
-#if !defined(XP_UNIX)
+#if !defined(XP_UNIX) || defined(XP_MACOSX)
     rv = file->AppendNative(NS_LITERAL_CSTRING("Profiles"));
 #endif
     // We must create the profile directory here if it does not exist.
@@ -201,7 +236,7 @@ nsXREDirProvider::GetUserProfilesLocalDir(nsIFile** aResult,
   return NS_OK;
 }
 
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) || defined(XP_MACOSX)
 /**
  * Get the directory that is the parent of the system-wide directories
  * for extensions and native-messaing manifests.
@@ -215,6 +250,12 @@ GetSystemParentDirectory(nsIFile** aFile)
 {
   nsresult rv;
   nsCOMPtr<nsIFile> localDir;
+#if defined(XP_MACOSX)
+  rv = GetOSXFolderType(kOnSystemDisk, kApplicationSupportFolderType, getter_AddRefs(localDir));
+  if (NS_SUCCEEDED(rv)) {
+    rv = localDir->AppendNative(NS_LITERAL_CSTRING("Mozilla"));
+  }
+#else
   NS_NAMED_LITERAL_CSTRING(dirname,
 #ifdef HAVE_USR_LIB64_DIR
                            "/usr/lib64/mozilla"
@@ -225,6 +266,7 @@ GetSystemParentDirectory(nsIFile** aFile)
 #endif
                            );
   rv = NS_NewNativeLocalFile(dirname, false, getter_AddRefs(localDir));
+#endif
 
   if (NS_SUCCEEDED(rv)) {
     localDir.forget(aFile);
@@ -308,14 +350,18 @@ nsXREDirProvider::GetFile(const char* aProperty, bool* aPersistent,
            !strcmp(aProperty, XRE_USER_APP_DATA_DIR)) {
     rv = GetUserAppDataDirectory(getter_AddRefs(file));
   }
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) || defined(XP_MACOSX)
   else if (!strcmp(aProperty, XRE_SYS_NATIVE_MESSAGING_MANIFESTS)) {
     nsCOMPtr<nsIFile> localDir;
 
     rv = ::GetSystemParentDirectory(getter_AddRefs(localDir));
     if (NS_SUCCEEDED(rv)) {
       NS_NAMED_LITERAL_CSTRING(dirname,
+#if defined(XP_MACOSX)
+                               "NativeMessagingHosts"
+#else
                                "native-messaging-hosts"
+#endif
                                );
       rv = localDir->AppendNative(dirname);
       if (NS_SUCCEEDED(rv)) {
@@ -327,10 +373,17 @@ nsXREDirProvider::GetFile(const char* aProperty, bool* aPersistent,
     nsCOMPtr<nsIFile> localDir;
     rv = GetUserDataDirectoryHome(getter_AddRefs(localDir), false);
     if (NS_SUCCEEDED(rv)) {
+#if defined(XP_MACOSX)
+      rv = localDir->AppendNative(NS_LITERAL_CSTRING("Mozilla"));
+      if (NS_SUCCEEDED(rv)) {
+        rv = localDir->AppendNative(NS_LITERAL_CSTRING("NativeMessagingHosts"));
+      }
+#else
       rv = localDir->AppendNative(NS_LITERAL_CSTRING(".mozilla"));
       if (NS_SUCCEEDED(rv)) {
         rv = localDir->AppendNative(NS_LITERAL_CSTRING("native-messaging-hosts"));
       }
+#endif
     }
     if (NS_SUCCEEDED(rv)) {
       localDir.swap(file);
@@ -372,7 +425,7 @@ nsXREDirProvider::GetFile(const char* aProperty, bool* aPersistent,
       return mAppProvider->GetFile(NS_APP_PROFILE_DIR_STARTUP, aPersistent,
                                    aFile);
   }
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) || defined(XP_MACOSX)
   else if (!strcmp(aProperty, XRE_SYS_LOCAL_EXTENSION_PARENT_DIR)) {
 #ifdef ENABLE_SYSTEM_EXTENSION_DIRS
     return GetSystemExtensionsDirectory(aFile);
@@ -381,7 +434,7 @@ nsXREDirProvider::GetFile(const char* aProperty, bool* aPersistent,
 #endif
   }
 #endif
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) && !defined(XP_MACOSX)
   else if (!strcmp(aProperty, XRE_SYS_SHARE_EXTENSION_PARENT_DIR)) {
 #ifdef ENABLE_SYSTEM_EXTENSION_DIRS
 #if defined(__OpenBSD__) || defined(__FreeBSD__)
@@ -1050,7 +1103,42 @@ nsXREDirProvider::GetUpdateRootDir(nsIFile* *aResult)
   rv = appFile->GetParent(getter_AddRefs(updRoot));
   NS_ENSURE_SUCCESS(rv, rv);
 
-#if XP_WIN
+#ifdef XP_MACOSX
+  nsCOMPtr<nsIFile> appRootDirFile;
+  nsCOMPtr<nsIFile> localDir;
+  nsAutoString appDirPath;
+  if (NS_FAILED(appFile->GetParent(getter_AddRefs(appRootDirFile))) ||
+      NS_FAILED(appRootDirFile->GetPath(appDirPath)) ||
+      NS_FAILED(GetUserDataDirectoryHome(getter_AddRefs(localDir), true))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t dotIndex = appDirPath.RFind(".app");
+  if (dotIndex == kNotFound) {
+    dotIndex = appDirPath.Length();
+  }
+  appDirPath = Substring(appDirPath, 1, dotIndex - 1);
+
+  bool hasVendor = gAppData->vendor && strlen(gAppData->vendor) != 0;
+  if (hasVendor || gAppData->name) {
+    if (NS_FAILED(localDir->AppendNative(nsDependentCString(hasVendor ?
+                                           gAppData->vendor :
+                                           gAppData->name)))) {
+      return NS_ERROR_FAILURE;
+    }
+  } else if (NS_FAILED(localDir->AppendNative(NS_LITERAL_CSTRING("Mozilla")))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (NS_FAILED(localDir->Append(NS_LITERAL_STRING("updates"))) ||
+      NS_FAILED(localDir->AppendRelativePath(appDirPath))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  localDir.forget(aResult);
+  return NS_OK;
+
+#elif XP_WIN
   nsAutoString pathHash;
   bool pathHashResult = false;
   bool hasVendor = gAppData->vendor && strlen(gAppData->vendor) != 0;
@@ -1192,7 +1280,32 @@ nsXREDirProvider::GetUserDataDirectoryHome(nsIFile** aFile, bool aLocal)
   nsresult rv;
   nsCOMPtr<nsIFile> localDir;
 
-#if defined(XP_WIN)
+#if defined(XP_MACOSX)
+  FSRef fsRef;
+  OSType folderType;
+  if (aLocal) {
+    folderType = kCachedDataFolderType;
+  } else {
+#ifdef MOZ_THUNDERBIRD
+    folderType = kDomainLibraryFolderType;
+#else
+    folderType = kApplicationSupportFolderType;
+#endif
+  }
+  OSErr err = ::FSFindFolder(kUserDomain, folderType, kCreateFolder, &fsRef);
+  NS_ENSURE_FALSE(err, NS_ERROR_FAILURE);
+
+  rv = NS_NewNativeLocalFile(EmptyCString(), true, getter_AddRefs(localDir));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsILocalFileMac> dirFileMac = do_QueryInterface(localDir);
+  NS_ENSURE_TRUE(dirFileMac, NS_ERROR_UNEXPECTED);
+
+  rv = dirFileMac->InitWithFSRef(&fsRef);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  localDir = do_QueryInterface(dirFileMac, &rv);
+#elif defined(XP_WIN)
   nsString path;
   if (aLocal) {
     rv = GetShellFolderPath(CSIDL_LOCAL_APPDATA, path);
@@ -1255,7 +1368,7 @@ nsXREDirProvider::GetSysUserExtensionsDirectory(nsIFile** aFile)
   return NS_OK;
 }
 
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) || defined(XP_MACOSX)
 nsresult
 nsXREDirProvider::GetSystemExtensionsDirectory(nsIFile** aFile)
 {
@@ -1265,7 +1378,11 @@ nsXREDirProvider::GetSystemExtensionsDirectory(nsIFile** aFile)
   rv = GetSystemParentDirectory(getter_AddRefs(localDir));
   if (NS_SUCCEEDED(rv)) {
     NS_NAMED_LITERAL_CSTRING(sExtensions,
+#if defined(XP_MACOSX)
+                             "Extensions"
+#else
                              "extensions"
+#endif
                              );
 
     rv = localDir->AppendNative(sExtensions);
@@ -1332,7 +1449,7 @@ nsXREDirProvider::AppendSysUserExtensionPath(nsIFile* aFile)
 
   nsresult rv;
 
-#if defined(XP_WIN)
+#if defined (XP_MACOSX) || defined(XP_WIN)
 
   static const char* const sXR = "Mozilla";
   rv = aFile->AppendNative(nsDependentCString(sXR));
@@ -1391,7 +1508,19 @@ nsXREDirProvider::AppendProfilePath(nsIFile* aFile,
 
   nsresult rv;
 
-#if defined(XP_WIN)
+#if defined (XP_MACOSX)
+  if (!profile.IsEmpty()) {
+    rv = AppendProfileString(aFile, profile.get());
+  }
+  else {
+    // Note that MacOS ignores the vendor when creating the profile hierarchy -
+    // all application preferences directories live alongside one another in
+    // ~/Library/Application Support/
+    rv = aFile->AppendNative(appName);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+#elif defined(XP_WIN)
   if (!profile.IsEmpty()) {
     rv = AppendProfileString(aFile, profile.get());
   }
diff --git a/toolkit/xre/nsXREDirProvider.h b/toolkit/xre/nsXREDirProvider.h
index 014317e641..655f664e6d 100644
--- a/toolkit/xre/nsXREDirProvider.h
+++ b/toolkit/xre/nsXREDirProvider.h
@@ -102,7 +102,7 @@ protected:
   nsresult GetFilesInternal(const char* aProperty, nsISimpleEnumerator** aResult);
   static nsresult GetUserDataDirectoryHome(nsIFile* *aFile, bool aLocal);
   static nsresult GetSysUserExtensionsDirectory(nsIFile* *aFile);
-#if defined(XP_UNIX)
+#if defined(XP_UNIX) || defined(XP_MACOSX)
   static nsresult GetSystemExtensionsDirectory(nsIFile** aFile);
 #endif
   static nsresult EnsureDirectoryExists(nsIFile* aDirectory);