--- a/.hgtags
+++ b/.hgtags
@@ -76,8 +76,13 @@ 462c726144bc1fb45b61e774f64ac5d61b4e047c
 bbc7014db2de49e2301680d2a86be8a53108a88a AURORA_BASE_20120131
 bbc7014db2de49e2301680d2a86be8a53108a88a AURORA_BASE_20120131
 0000000000000000000000000000000000000000 AURORA_BASE_20120131
 0000000000000000000000000000000000000000 AURORA_BASE_20120131
 bbc7014db2de49e2301680d2a86be8a53108a88a AURORA_BASE_20120131
 b6627f28b7ec17e1b46a594df0f780d3a40847e4 FIREFOX_AURORA_13_BASE
 357da346ceb705d196a46574804c7c4ec44ac186 FIREFOX_AURORA_14_BASE
 26dcd1b1a20893ad99341c61c6b1239ff1523858 FIREFOX_AURORA_15_BASE
+0accd12a8e7e217836ea3f1ee7c411913fc75d8e FIREFOX_AURORA_16_BASE
+0000000000000000000000000000000000000000 FIREFOX_AURORA_16_BASE
+9697eadafa13b4e9233b39aaeecfeac79503cb54 FIREFOX_AURORA_16_BASE
+9697eadafa13b4e9233b39aaeecfeac79503cb54 FIREFOX_AURORA_16_BASE
+6fdf9985acfe6f939da584b2559464ab22264fe7 FIREFOX_AURORA_16_BASE

--- a/accessible/src/base/RoleMap.h
+++ b/accessible/src/base/RoleMap.h
@@ -826,17 +826,17 @@ ROLE(COMBOBOX_OPTION,
      ATK_ROLE_MENU_ITEM,
      NSAccessibilityMenuItemRole,
      ROLE_SYSTEM_LISTITEM,
      ROLE_SYSTEM_LISTITEM)
 
 ROLE(IMAGE_MAP,
      "image map",
      ATK_ROLE_IMAGE,
-     NSAccessibilityImageRole,
+     NSAccessibilityUnknownRole,
      ROLE_SYSTEM_GRAPHIC,
      ROLE_SYSTEM_GRAPHIC)
 
 ROLE(OPTION,
      "listbox option",
      ATK_ROLE_LIST_ITEM,
      NSAccessibilityRowRole,
      ROLE_SYSTEM_LISTITEM,

--- a/accessible/src/base/nsAccDocManager.h
+++ b/accessible/src/base/nsAccDocManager.h
@@ -19,17 +19,17 @@ class DocAccessible;
 /**
  * Manage the document accessible life cycle.
  */
 class nsAccDocManager : public nsIWebProgressListener,
                         public nsIDOMEventListener,
                         public nsSupportsWeakReference
 {
 public:
-  virtual ~nsAccDocManager() { };
+  virtual ~nsAccDocManager() { }
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSIWEBPROGRESSLISTENER
   NS_DECL_NSIDOMEVENTLISTENER
 
   /**
    * Return document accessible for the given DOM node.
    */
@@ -65,17 +65,17 @@ public:
     mDocAccessibleCache.Remove(aDocument);
   }
 
 #ifdef DEBUG
   bool IsProcessingRefreshDriverNotification() const;
 #endif
 
 protected:
-  nsAccDocManager() { };
+  nsAccDocManager() { }
 
   /**
    * Initialize the manager.
    */
   bool Init();
 
   /**
    * Shutdown the manager.

--- a/accessible/src/mac/mozAccessible.mm
+++ b/accessible/src/mac/mozAccessible.mm
@@ -407,17 +407,17 @@ GetClosestInterestingAccessible(id anObj
   NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
 }
 
 - (NSString*)role
 {
   if (!mGeckoAccessible)
     return nil;
 
-#ifdef DEBUG
+#ifdef DEBUG_A11Y
   NS_ASSERTION(nsAccUtils::IsTextInterfaceSupportCorrect(mGeckoAccessible),
                "Does not support nsIAccessibleText when it should");
 #endif
 
 #define ROLE(geckoRole, stringRole, atkRole, macRole, msaaRole, ia2Role) \
   case roles::geckoRole: \
     return macRole;
 

--- a/accessible/src/mac/mozHTMLAccessible.mm
+++ b/accessible/src/mac/mozHTMLAccessible.mm
@@ -87,16 +87,26 @@
     return;
 
   if ([action isEqualToString:NSAccessibilityPressAction])
     mGeckoAccessible->DoAction(0);
   else
     [super accessibilityPerformAction:action];
 }
 
+- (NSString*)customDescription
+{
+  return @"";
+}
+
+- (NSString*)value
+{
+  return @"";
+}
+
 - (NSURL*)url
 {
   if (!mGeckoAccessible || mGeckoAccessible->IsDefunct())
     return nil;
 
   nsAutoString value;
   mGeckoAccessible->Value(value);
 

--- a/accessible/tests/mochitest/events/test_focus_autocomplete.xul
+++ b/accessible/tests/mochitest/events/test_focus_autocomplete.xul
@@ -225,17 +225,17 @@
             var itemX = {}, itemY = {}, treeX = {}, treeY = {};
             accessible.getBounds(itemX, itemY, {}, {});
             tree.getBounds(treeX, treeY, {}, {});
             x = itemX.value - treeX.value;
             y = itemY.value - treeY.value;
           }
         }
 
-        synthesizeMouse(node, x + 1, y + 1, {}, targetWindow);
+        synthesizeMouseAtCenter(node, {}, targetWindow);
       }
 
       this.getID = function selectByClick_getID()
       {
         return "select by click " + prettyName(aIDFunc.call(null, aIDFuncArg));
       }
     }
 

--- a/accessible/tests/mochitest/tree/test_map.html
+++ b/accessible/tests/mochitest/tree/test_map.html
@@ -17,19 +17,19 @@
     function doTest()
     {
       // map used as imagemap, not accessible
       var accTree =
         { SECTION: [ ] };
 
       testAccessibleTree("imagemapcontainer", accTree);
 
-      // map group
+      // map group.  Imagemaps are inlines by default, so TEXT_CONTAINER.
       accTree =
-        { PARAGRAPH: [
+        { TEXT_CONTAINER: [
           { PARAGRAPH: [
             { TEXT_LEAF: [ ] },
             { LINK: [
               { TEXT_LEAF: [ ] }
             ] },
             { TEXT_LEAF: [ ] },
             { LINK: [
               { TEXT_LEAF: [ ] }

--- a/accessible/tests/mochitest/treeupdate/test_imagemap.html
+++ b/accessible/tests/mochitest/treeupdate/test_imagemap.html
@@ -422,13 +422,16 @@
   <map name="atoz_map" id="map">
     <area href="http://www.bbc.co.uk/radio4/atoz/index.shtml#b"
           coords="17,0,30,14" alt="b" shape="rect">
   </map>
 
   <div id="container">
     <img id="imgmap" width="447" height="15"
          usemap="#atoz_map"
-         src="../letters.gif">
-  </div>
+         src="../letters.gif"><!--
+    Important: no whitespace between the <img> and the </div>, so we
+    don't end up with textframes there, because those would be reflected
+    in our accessible tree in some cases.
+    --></div>
 
 </body>
 </html>

--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -240,17 +240,18 @@ pref("editor.singleLine.pasteNewlines", 
 
 // threshold where a tap becomes a drag, in 1/240" reference pixels
 // The names of the preferences are to be in sync with nsEventStateManager.cpp
 pref("ui.dragThresholdX", 25);
 pref("ui.dragThresholdY", 25);
 
 // Layers Acceleration
 pref("layers.acceleration.disabled", false);
-pref("layers.offmainthreadcomposition.enabled", false);
+pref("layers.offmainthreadcomposition.enabled", true);
+pref("layers.async-video.enabled", true);
 
 // Web Notifications
 pref("notification.feature.enabled", true);
 
 // IndexedDB
 pref("indexedDB.feature.enabled", true);
 pref("dom.indexedDB.warningQuota", 5);
 
@@ -404,16 +405,26 @@ pref("b2g.remote-js.port", 9999);
 // Handle hardware buttons in the b2g chrome package
 pref("b2g.keys.menu.enabled", true);
 
 // Screen timeout in seconds
 pref("power.screen.timeout", 60);
 
 pref("full-screen-api.enabled", true);
 
+#ifndef MOZ_WIDGET_GONK
+// If we're not actually on physical hardware, don't make the top level widget
+// fullscreen when transitioning to fullscreen. This means in emulated
+// environments (like the b2g desktop client) we won't make the client window
+// fill the whole screen, we'll just make the content fill the client window,
+// i.e. it won't give the impression to content that the number of device
+// screen pixels changes!
+pref("full-screen-api.ignore-widgets", true);
+#endif
+
 pref("media.volume.steps", 10);
 
 //Enable/disable marionette server, set listening port
 pref("marionette.defaultPrefs.enabled", true);
 pref("marionette.defaultPrefs.port", 2828);
 
 #ifdef MOZ_UPDATER
 pref("app.update.enabled", true);
@@ -455,8 +466,14 @@ pref("media.plugins.enabled", true);
 // Disable printing (particularly, window.print())
 pref("dom.disable_window_print", true);
 
 // Disable window.showModalDialog
 pref("dom.disable_window_showModalDialog", true);
 
 // Turns on gralloc-based direct texturing for Gonk
 pref("gfx.gralloc.enabled", false);
+
+// XXXX REMOVE FOR PRODUCTION. Turns on GC and CC logging 
+pref("javascript.options.mem.log", true);
+
+// Increase mark slice time from 10ms to 30ms
+pref("javascript.options.mem.gc_incremental_slice_ms", 30);

--- a/b2g/chrome/content/settings.js
+++ b/b2g/chrome/content/settings.js
@@ -42,16 +42,25 @@ var SettingsListener = {
     }));
 
     this._callbacks[name] = callback;
   }
 };
 
 SettingsListener.init();
 
+// =================== Audio ====================
+SettingsListener.observe('audio.volume.master', 0.5, function(value) {
+  let audioManager = Services.audioManager;
+  if (!audioManager)
+    return;
+
+  audioManager.masterVolume = Math.max(0.0, Math.min(value, 1.0));
+});
+
 
 // =================== Languages ====================
 SettingsListener.observe('language.current', 'en-US', function(value) {
   Services.prefs.setCharPref('intl.accept_languages', value);
 });
 
 
 // =================== RIL ====================

--- a/b2g/chrome/content/shell.js
+++ b/b2g/chrome/content/shell.js
@@ -171,69 +171,32 @@ var shell = {
     window.removeEventListener('sizemodechange', this);
     this.contentBrowser.removeEventListener('mozbrowserloadstart', this, true);
 
 #ifndef MOZ_WIDGET_GONK
     delete Services.audioManager;
 #endif
   },
 
-  changeVolume: function shell_changeVolume(delta) {
-    let steps = 10;
-    try {
-      steps = Services.prefs.getIntPref("media.volume.steps");
-      if (steps <= 0)
-        steps = 1;
-    } catch(e) {}
-
-    let audioManager = Services.audioManager;
-    if (!audioManager)
-      return;
-
-    let currentVolume = audioManager.masterVolume;
-    let newStep = Math.round(steps * Math.sqrt(currentVolume)) + delta;
-    let volume = (newStep / steps) * (newStep / steps);
-
-    if (volume > 1)
-      volume = 1;
-    if (volume < 0)
-      volume = 0;
-    audioManager.masterVolume = volume;
-  },
-
   forwardKeyToContent: function shell_forwardKeyToContent(evt) {
     let content = shell.contentBrowser.contentWindow;
     let generatedEvent = content.document.createEvent('KeyboardEvent');
     generatedEvent.initKeyEvent(evt.type, true, true, evt.view, evt.ctrlKey,
                                 evt.altKey, evt.shiftKey, evt.metaKey,
                                 evt.keyCode, evt.charCode);
 
     content.document.documentElement.dispatchEvent(generatedEvent);
   },
 
   handleEvent: function shell_handleEvent(evt) {
     let content = this.contentBrowser.contentWindow;
     switch (evt.type) {
       case 'keydown':
       case 'keyup':
       case 'keypress':
-        // For debug purposes and because some of the APIs are not yet exposed
-        // to the content, let's react on some of the keyup events.
-        if (evt.type == 'keyup' && evt.eventPhase == evt.BUBBLING_PHASE) {
-          switch (evt.keyCode) {
-            case evt.DOM_VK_PAGE_DOWN:
-              this.changeVolume(-1);
-              break;
-
-            case evt.DOM_VK_PAGE_UP:
-              this.changeVolume(1);
-              break;
-          }
-        }
-
         // Redirect the HOME key to System app and stop the applications from
         // handling it.
         let rootContentEvt = (evt.target.ownerDocument.defaultView == content);
         if (!rootContentEvt && evt.eventPhase == evt.CAPTURING_PHASE &&
             evt.keyCode == evt.DOM_VK_HOME) {
           this.forwardKeyToContent(evt);
           evt.preventDefault();
           evt.stopImmediatePropagation();

--- a/b2g/confvars.sh
+++ b/b2g/confvars.sh
@@ -1,16 +1,16 @@
 # 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/.
 
 MOZ_APP_BASENAME=B2G
 MOZ_APP_VENDOR=Mozilla
 
-MOZ_APP_VERSION=16.0a1
+MOZ_APP_VERSION=17.0a1
 MOZ_APP_UA_NAME=Firefox
 
 MOZ_BRANDING_DIRECTORY=b2g/branding/unofficial
 MOZ_OFFICIAL_BRANDING_DIRECTORY=b2g/branding/official
 # MOZ_APP_DISPLAYNAME is set by branding/configure.sh
 
 MOZ_SAFE_BROWSING=
 MOZ_SERVICES_SYNC=1

--- a/browser/app/blocklist.xml
+++ b/browser/app/blocklist.xml
@@ -1,10 +1,10 @@
 <?xml version="1.0"?>
-<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1341001222000">
+<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1341959296000">
   <emItems>
       <emItem  blockID="i58" id="webmaster@buzzzzvideos.info">
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i86" id="{45147e67-4020-47e2-8f7a-55464fb535aa}">
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
@@ -23,17 +23,17 @@
                   </emItem>
       <emItem  blockID="i43" id="supportaccessplugin@gmail.com">
                         </emItem>
       <emItem  blockID="i82" id="{8f42fb8b-b6f6-45de-81c0-d6d39f54f971}">
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i107" os="WINNT" id="{ABDE892B-13A8-4d1b-88E6-365A6E755758}">
-                        <versionRange  minVersion="0" maxVersion="15.0.4" severity="1">
+                        <versionRange  minVersion="0" maxVersion="15.0.5" severity="1">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i88" id="anttoolbar@ant.com">
                         <versionRange  minVersion="2.4.6.4" maxVersion="2.4.6.4" severity="1">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i17" id="{3252b9ae-c69a-4eaf-9502-dc9c1f6c009e}">
                         <versionRange  minVersion="2.2" maxVersion="2.2">
@@ -210,16 +210,20 @@
       <emItem  blockID="i109" id="{392e123b-b691-4a5e-b52f-c4c1027e749c}">
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i60" id="youtb3@youtb3.com">
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
                   </emItem>
+      <emItem  blockID="i111" os="WINNT" id="{C3949AC2-4B17-43ee-B4F1-D26B9D42404D}">
+                        <versionRange  minVersion="0" maxVersion="15.0.5" severity="1">
+                    </versionRange>
+                  </emItem>
       <emItem  blockID="i38" id="{B7082FAA-CB62-4872-9106-E42DD88EDE45}">
                         <versionRange  minVersion="0.1" maxVersion="3.3.0.*">
                       <targetApplication  id="{ec8030f7-c20a-464f-9b0e-13a3a9e97384}">
                               <versionRange  minVersion="3.7a1" maxVersion="*" />
                           </targetApplication>
                     </versionRange>
                                 <versionRange  minVersion="3.3.1" maxVersion="*">
                       <targetApplication  id="{ec8030f7-c20a-464f-9b0e-13a3a9e97384}">
@@ -323,17 +327,17 @@
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i77" id="{fa277cfc-1d75-4949-a1f9-4ac8e41b2dfd}">
                         <versionRange  minVersion="0" maxVersion="*">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i106" os="WINNT" id="{97E22097-9A2F-45b1-8DAF-36AD648C7EF4}">
-                        <versionRange  minVersion="0" maxVersion="15.0.4" severity="1">
+                        <versionRange  minVersion="0" maxVersion="15.0.5" severity="1">
                     </versionRange>
                   </emItem>
       <emItem  blockID="i11" id="yslow@yahoo-inc.com">
                         <versionRange  minVersion="2.0.5" maxVersion="2.0.5">
                       <targetApplication  id="{ec8030f7-c20a-464f-9b0e-13a3a9e97384}">
                               <versionRange  minVersion="3.5.7" maxVersion="*" />
                           </targetApplication>
                     </versionRange>

--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1179,9 +1179,9 @@ pref("pdfjs.previousHandler.preferredAct
 pref("pdfjs.previousHandler.alwaysAskBeforeHandling", false);
 
 // The maximum amount of decoded image data we'll willingly keep around (we
 // might keep around more than this, but we'll try to get down to this value).
 // (This is intentionally on the high side; see bug 746055.)
 pref("image.mem.max_decoded_image_kb", 256000);
 
 // Example social provider
-pref("social.manifest.motown", "{\"origin\":\"https://motown-dev.mozillalabs.com\",\"name\":\"MoTown\",\"workerURL\":\"https://motown-dev.mozillalabs.com/social/worker.js\"}");
+pref("social.manifest.motown", "{\"origin\":\"https://motown-dev.mozillalabs.com\",\"name\":\"MoTown\",\"workerURL\":\"https://motown-dev.mozillalabs.com/social/worker.js\",\"iconURL\":\"https://motown-dev.mozillalabs.com/images/motown-icon.png\"}");

--- a/browser/base/content/aboutRobots.xhtml
+++ b/browser/base/content/aboutRobots.xhtml
@@ -44,17 +44,17 @@
     <style type="text/css"><![CDATA[
       #errorPageContainer:before {
         content: url('chrome://browser/content/aboutRobots-icon.png');
         position: absolute;
       }
 
       body[dir=rtl] #icon,
       body[dir=rtl] #errorPageContainer:before {
-        -moz-transform: scaleX(-1);
+        transform: scaleX(-1);
       }
     ]]></style>
   </head>
 
   <body dir="&locale.dir;">
 
     <!-- PAGE CONTAINER (for styling purposes only) -->
     <div id="errorPageContainer">
@@ -92,13 +92,13 @@
       <!-- Button -->
       <button id="errorTryAgain"
               label2="&robots.dontpress;"
               onclick="robotButton();">&retry.label;</button>
 
       <img src="chrome://browser/content/aboutRobots-widget-left.png"
            style="position: absolute; bottom: -12px; left: -10px;"/>
       <img src="chrome://browser/content/aboutRobots-widget-left.png"
-           style="position: absolute; bottom: -12px; right: -10px; -moz-transform: scaleX(-1);"/>
+           style="position: absolute; bottom: -12px; right: -10px; transform: scaleX(-1);"/>
     </div>
 
   </body>
 </html>

--- a/browser/base/content/abouthome/aboutHome.css
+++ b/browser/base/content/abouthome/aboutHome.css
@@ -38,16 +38,17 @@ a {
 }
 
 #topSection {
   text-align: center;
 }
 
 #brandLogo {
   height: 154px;
+  width: 154px;
   margin: 22px 0 31px;
 }
 
 #searchForm,
 #snippets {
   width: 470px;
 }
 
@@ -59,16 +60,18 @@ a {
   display: -moz-box;
   -moz-box-align: center;
   padding-top: 2px;
   -moz-padding-end: 8px;
 }
 
 #searchEngineLogo {
   display: inline-block;
+  height: 28px;
+  width: 70px;
 }
 
 #searchText {
   -moz-box-flex: 1;
   padding: 6px 8px;
   background: hsla(0,0%,100%,.9) padding-box;
   border: 1px solid;
   border-color: hsla(210,54%,20%,.15) hsla(210,54%,20%,.17) hsla(210,54%,20%,.2);
@@ -77,17 +80,18 @@ a {
               0 1px 0 hsla(0,0%,100%,.2);
   border-radius: 2.5px 0 0 2.5px;
 }
 
 body[dir=rtl] #searchText {
   border-radius: 0 2.5px 2.5px 0;
 }
 
-#searchText:focus {
+#searchText:focus,
+#searchText[autofocus] {
   border-color: hsla(206,100%,60%,.6) hsla(206,76%,52%,.6) hsla(204,100%,40%,.6);
 }
 
 #searchSubmit {
   -moz-margin-start: -1px;
   background: -moz-linear-gradient(hsla(0,0%,100%,.8), hsla(0,0%,100%,.1)) padding-box;
   padding: 0 9px;
   border: 1px solid;
@@ -101,22 +105,24 @@ body[dir=rtl] #searchText {
   transition-duration: 150ms;
 }
 
 body[dir=rtl] #searchSubmit {
   border-radius: 2.5px 0 0 2.5px;
 }
 
 #searchText:focus + #searchSubmit,
-#searchText + #searchSubmit:hover {
+#searchText + #searchSubmit:hover,
+#searchText[autofocus] + #searchSubmit {
   border-color: #59b5fc #45a3e7 #3294d5;
   color: white;
 }
 
-#searchText:focus + #searchSubmit {
+#searchText:focus + #searchSubmit,
+#searchText[autofocus] + #searchSubmit {
   background-image: -moz-linear-gradient(#4cb1ff, #1793e5);
   box-shadow: 0 1px 0 hsla(0,0%,100%,.2) inset,
               0 0 0 1px hsla(0,0%,100%,.1) inset,
               0 1px 0 hsla(210,54%,20%,.03);
 }
 
 #searchText + #searchSubmit:hover {
   background-image: -moz-linear-gradient(#66bdff, #0d9eff);
@@ -155,16 +161,22 @@ body[dir=rtl] #defaultSnippet2 {
 }
 
 #snippets {
   display: inline-block;
   text-align: start;
   margin: 12px 0;
   color: #3c3c3c;
   font-size: 75%;
+  /* 12px is the computed font size, 15px the computed line height of the snippets
+     with Segoe UI on a default Windows 7 setup. The 15/12 multiplier approximately
+     converts em from units of font-size to units of line-height. The goal is to
+     preset the height of a three-line snippet to avoid visual moving/flickering as
+     the snippets load. */
+  min-height: -moz-calc(15/12 * 3em);
 }
 
 #launcher {
   display: -moz-box;
   -moz-box-align: center;
   -moz-box-pack: center;
   width: 100%;
   background-color: hsla(0,0%,0%,.03);
@@ -251,18 +263,19 @@ body[narrow] #restorePreviousSessionSepa
 }
 
 body[narrow] #restorePreviousSession {
   font-size: 80%;
 }
 
 .launchButton::before {
   display: block;
+  width: 32px;
   height: 32px;
-  margin-bottom: 6px;
+  margin: 0 auto 6px;
   line-height: 0; /* remove extra vertical space due to non-zero font-size */
 }
 
 #downloads::before {
   content: url("chrome://browser/content/abouthome/downloads.png");
 }
 
 #bookmarks::before {
@@ -295,17 +308,17 @@ body[narrow] #restorePreviousSession {
   width: 48px;
   display: inline-block; /* display on same line as text label */
   vertical-align: middle;
   margin-bottom: 0;
   -moz-margin-end: 8px;
 }
 
 body[dir=rtl] #restorePreviousSession::before {
-  -moz-transform: scaleX(-1);
+  transform: scaleX(-1);
 }
 
 body[narrow] #restorePreviousSession::before {
   content: url("chrome://browser/content/abouthome/restore.png");
   height: 32px;
   width: 32px;
 }
 

--- a/browser/base/content/abouthome/aboutHome.js
+++ b/browser/base/content/abouthome/aboutHome.js
@@ -160,16 +160,25 @@ function setupSearchEngine()
 
   // Add search engine logo.
   if (gSearchEngine.image) {
     let logoElt = document.getElementById("searchEngineLogo");
     logoElt.src = gSearchEngine.image;
     logoElt.alt = gSearchEngine.name;
   }
 
+  // The "autofocus" attribute doesn't focus the form element
+  // immediately when the element is first drawn, so the
+  // attribute is also used for styling when the page first loads.
+  let searchText = document.getElementById("searchText");
+  searchText.addEventListener("blur", function searchText_onBlur() {
+    searchText.removeEventListener("blur", searchText_onBlur);
+    searchText.removeAttribute("autofocus");
+  });
+
 }
 
 function loadSnippets()
 {
   // Check last snippets update.
   let lastUpdate = localStorage["snippets-last-update"];
   let updateURL = localStorage["snippets-update-url"];
   if (updateURL && (!lastUpdate ||

--- a/browser/base/content/browser-sets.inc
+++ b/browser/base/content/browser-sets.inc
@@ -100,16 +100,18 @@
     <command id="Tools:ResponsiveUI" oncommand="ResponsiveUI.toggle();" disabled="true"/>
     <command id="Tools:Addons" oncommand="BrowserOpenAddonsMgr();"/>
     <command id="Tools:Sanitize"
      oncommand="Cc['@mozilla.org/browser/browserglue;1'].getService(Ci.nsIBrowserGlue).sanitize(window);"/>
     <command id="Tools:PrivateBrowsing" oncommand="gPrivateBrowsingUI.toggleMode();"/>
     <command id="History:UndoCloseTab" oncommand="undoCloseTab();"/>
     <command id="History:UndoCloseWindow" oncommand="undoCloseWindow();"/>
     <command id="Browser:ToggleAddonBar" oncommand="toggleAddonBar();"/>
+    <command id="Social:SharePage" oncommand="SocialShareButton.sharePage();"/>
+    <command id="Social:UnsharePage" oncommand="SocialShareButton.unsharePage();"/>
   </commandset>
 
   <commandset id="placesCommands">
     <command id="Browser:ShowAllBookmarks"
              oncommand="PlacesCommandHook.showPlacesOrganizer('AllBookmarks');"/>
     <command id="Browser:ShowAllHistory"
              oncommand="PlacesCommandHook.showPlacesOrganizer('History');"/>
   </commandset>
@@ -332,16 +334,17 @@
     <key id="manBookmarkKb" key="&bookmarksGtkCmd.commandkey;" command="Browser:ShowAllBookmarks" modifiers="accel,shift"/>
 #endif
     <key id="viewBookmarksSidebarKb" key="&bookmarksCmd.commandkey;" command="viewBookmarksSidebar" modifiers="accel"/>
 #ifdef XP_WIN
 # Cmd+I is conventially mapped to Info on MacOS X, thus it should not be
 # overridden for other purposes there.
     <key id="viewBookmarksSidebarWinKb" key="&bookmarksWinCmd.commandkey;" command="viewBookmarksSidebar" modifiers="accel"/>
 #endif
+    <key id="sharePage" key="&sharePageCmd.commandkey;" command="Social:SharePage" modifiers="accel,shift"/>
 
 # don't use |command="Browser:Stop"|, ESC is being used to freeze animated gifs,
 # even if the stop button and menuitem are disabled (see Bug 284140)
     <key id="key_stop" keycode="VK_ESCAPE" oncommand="BrowserStop();"/>
 
 #ifdef XP_MACOSX
     <key id="key_stop_mac" modifiers="accel" key="&stopCmd.macCommandKey;" oncommand="BrowserStop();"/>
 #endif

new file mode 100644
--- /dev/null
+++ b/browser/base/content/browser-social.js
@@ -0,0 +1,256 @@
+// 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/.
+
+let SocialUI = {
+  // Called on delayed startup to initialize UI
+  init: function SocialUI_init() {
+    Services.obs.addObserver(this, "social:pref-changed", false);
+    Services.obs.addObserver(this, "social:ambient-notification-changed", false);
+    Services.obs.addObserver(this, "social:profile-changed", false);
+
+    Social.init(this._providerReady.bind(this));
+  },
+
+  // Called on window unload
+  uninit: function SocialUI_uninit() {
+    Services.obs.removeObserver(this, "social:pref-changed");
+    Services.obs.removeObserver(this, "social:ambient-notification-changed");
+    Services.obs.removeObserver(this, "social:profile-changed");
+  },
+
+  showProfile: function SocialUI_showProfile() {
+    if (Social.provider)
+      openUILink(Social.provider.profile.profileURL);
+  },
+
+  observe: function SocialUI_observe(subject, topic, data) {
+    switch (topic) {
+      case "social:pref-changed":
+        SocialShareButton.updateButtonHiddenState();
+        SocialToolbar.updateButtonHiddenState();
+        break;
+      case "social:ambient-notification-changed":
+        SocialToolbar.updateButton();
+        break;
+      case "social:profile-changed":
+        SocialToolbar.updateProfile();
+        break;
+    }
+  },
+
+  // Called once Social.jsm's provider has been set
+  _providerReady: function SocialUI_providerReady() {
+    SocialToolbar.init();
+    SocialShareButton.init();
+  }
+}
+
+let SocialShareButton = {
+  init: function SSB_init() {
+    this.sharePopup.hidden = false;
+    this.updateButtonHiddenState();
+
+    let profileRow = document.getElementById("editSharePopupHeader");
+    let profile = Social.provider.profile;
+    if (profile && profile.portrait && profile.displayName) {
+      profileRow.hidden = false;
+      let portrait = document.getElementById("socialUserPortrait");
+      portrait.style.listStyleImage = profile.portrait;
+      let displayName = document.getElementById("socialUserDisplayName");
+      displayName.setAttribute("label", profile.displayName);
+    } else {
+      profileRow.hidden = true;
+    }
+  },
+
+  get shareButton() {
+    return document.getElementById("share-button");
+  },
+  get sharePopup() {
+    return document.getElementById("editSharePopup");
+  },
+
+  dismissSharePopup: function SSB_dismissSharePopup() {
+    this.sharePopup.hidePopup();
+  },
+
+  updateButtonHiddenState: function SSB_updateButtonHiddenState() {
+    let shareButton = this.shareButton;
+    if (shareButton)
+      shareButton.hidden = !Social.uiVisible;
+  },
+
+  onClick: function SSB_onClick(aEvent) {
+    if (aEvent.button != 0)
+      return;
+
+    // Don't bubble to the textbox, to avoid unwanted selection of the address.
+    aEvent.stopPropagation();
+
+    this.sharePage();
+  },
+
+  panelShown: function SSB_panelShown(aEvent) {
+    let sharePopupOkButton = document.getElementById("editSharePopupOkButton");
+    if (sharePopupOkButton)
+      sharePopupOkButton.focus();
+  },
+
+  sharePage: function SSB_sharePage() {
+    let uri = gBrowser.currentURI;
+    if (!Social.isPageShared(uri)) {
+      Social.sharePage(uri);
+      this.updateShareState();
+    } else {
+      this.sharePopup.openPopup(this.shareButton, "bottomcenter topright");
+    }
+  },
+
+  unsharePage: function SSB_unsharePage() {
+    Social.unsharePage(gBrowser.currentURI);
+    this.updateShareState();
+    this.dismissSharePopup();
+  },
+
+  updateShareState: function SSB_updateShareState() {
+    let currentPageShared = Social.isPageShared(gBrowser.currentURI);
+
+    // Provide a11y-friendly notification of share.
+    let status = document.getElementById("share-button-status");
+    if (status) {
+      let statusString = currentPageShared ?
+                           gNavigatorBundle.getString("social.pageShared.label") : "";
+      status.setAttribute("value", statusString);
+    }
+
+    // Update the share button, if present
+    let shareButton = this.shareButton;
+    if (!shareButton)
+      return;
+
+    if (currentPageShared) {
+      shareButton.setAttribute("shared", "true");
+      shareButton.setAttribute("tooltiptext", gNavigatorBundle.getString("social.shareButton.sharedtooltip"));
+    } else {
+      shareButton.removeAttribute("shared");
+      shareButton.setAttribute("tooltiptext", gNavigatorBundle.getString("social.shareButton.tooltip"));
+    }
+  }
+};
+
+var SocialToolbar = {
+  // Called once, after window load, when the Social.provider object is initialized
+  init: function SocialToolbar_init() {
+    document.getElementById("social-provider-image").setAttribute("image", Social.provider.iconURL);
+    
+    // handle button state
+    document.getElementById("social-statusarea-popup").addEventListener("popupshowing", function(e) {
+      document.getElementById("social-toolbar-button").setAttribute("open", "true");
+    }, false);
+    document.getElementById("social-statusarea-popup").addEventListener("popuphiding", function(e) {
+      document.getElementById("social-toolbar-button").removeAttribute("open");
+    }, false);
+
+    this.updateButton();
+    this.updateProfile();
+  },
+
+  updateButtonHiddenState: function SocialToolbar_updateButtonHiddenState() {
+    let toolbarbutton = document.getElementById("social-toolbar-button");
+    toolbarbutton.hidden = !Social.uiVisible;
+  },
+
+  updateProfile: function SocialToolbar_updateProfile() {
+    // Profile may not have been initialized yet, since it depends on a worker
+    // response. In that case we'll be called again when it's available, via
+    // social:profile-changed
+    let profile = Social.provider.profile || {};
+    let userPortrait = profile.portrait || "chrome://browser/skin/social/social.png";
+    document.getElementById("social-statusarea-user-portrait").setAttribute("src", userPortrait);
+
+    let notLoggedInLabel = document.getElementById("social-statusarea-notloggedin");
+    let userNameBtn = document.getElementById("social-statusarea-username");
+    if (profile.userName) {
+      notLoggedInLabel.hidden = true;
+      userNameBtn.hidden = false;
+      userNameBtn.label = profile.userName;
+    } else {
+      notLoggedInLabel.hidden = false;
+      userNameBtn.hidden = true;
+    }
+  },
+
+  updateButton: function SocialToolbar_updateButton() {
+    this.updateButtonHiddenState();
+
+    let provider = Social.provider;
+    // if there are no ambient icons, we collapse them in the following loop
+    let iconNames = Object.keys(provider.ambientNotificationIcons);
+    let iconBox = document.getElementById("social-status-iconbox");
+    for (var i = 0; i < iconBox.childNodes.length; i++) {
+      let iconContainer = iconBox.childNodes[i];
+      if (i > iconNames.length - 1) {
+        iconContainer.collapsed = true;
+        continue;
+      }
+
+      iconContainer.collapsed = false;
+      let icon = provider.ambientNotificationIcons[iconNames[i]];
+      let iconImage = iconContainer.firstChild;
+      let iconCounter = iconImage.nextSibling;
+
+      iconImage.setAttribute("contentPanel", icon.contentPanel);
+      iconImage.setAttribute("src", icon.iconURL);
+
+      if (iconCounter.firstChild)
+        iconCounter.removeChild(iconCounter.firstChild);
+
+      if (icon.counter) {
+        iconCounter.appendChild(document.createTextNode(icon.counter));
+        iconCounter.collapsed = false;
+      } else {
+        iconCounter.collapsed = true;
+      }
+    }
+  },
+
+  showAmbientPopup: function SocialToolbar_showAmbientPopup(iconContainer) {
+    let iconImage = iconContainer.firstChild;
+    let panel = document.getElementById("social-notification-panel");
+    let notifBrowser = document.getElementById("social-notification-browser");
+
+    panel.hidden = false;
+
+    function sizePanelToContent() {
+      // XXX Maybe we can use nsIDOMWindowUtils.getRootBounds() here?
+      // XXX need to handle dynamic sizing
+      let doc = notifBrowser.contentDocument;
+      // XXX "notif" is an implementation detail that we should get rid of
+      // eventually
+      let body = doc.getElementById("notif") || doc.body.firstChild;
+      if (!body)
+        return;
+      let h = body.scrollHeight > 0 ? body.scrollHeight : 300;
+      notifBrowser.style.width = body.scrollWidth + "px";
+      notifBrowser.style.height = h + "px";
+    }
+
+    notifBrowser.addEventListener("DOMContentLoaded", function onload() {
+      notifBrowser.removeEventListener("DOMContentLoaded", onload);
+      sizePanelToContent();
+    });
+
+    panel.addEventListener("popuphiding", function onpopuphiding() {
+      panel.removeEventListener("popuphiding", onpopuphiding);
+      // unload the panel
+      document.getElementById("social-toolbar-button").removeAttribute("open");
+      notifBrowser.setAttribute("src", "about:blank");
+    });
+
+    notifBrowser.service = Social.provider;
+    notifBrowser.setAttribute("src", iconImage.getAttribute("contentPanel"));
+    document.getElementById("social-toolbar-button").setAttribute("open", "true");
+    panel.openPopup(iconImage, "bottomcenter topleft", 0, 0, false, false);
+  }
+}

--- a/browser/base/content/browser-syncui.js
+++ b/browser/base/content/browser-syncui.js
@@ -136,17 +136,17 @@ let gSyncUI = {
 
   onLoginFinish: function SUI_onLoginFinish() {
     // Clear out any login failure notifications
     let title = this._stringBundle.GetStringFromName("error.login.title");
     this.clearError(title);
   },
 
   onSetupComplete: function SUI_onSetupComplete() {
-    onLoginFinish();
+    this.onLoginFinish();
   },
 
   onLoginError: function SUI_onLoginError() {
     // if login fails, any other notifications are essentially moot
     Weave.Notifications.removeAll();
 
     // if we haven't set up the client, don't show errors
     if (this._needsSetup()) {

--- a/browser/base/content/browser-tabPreviews.js
+++ b/browser/base/content/browser-tabPreviews.js
@@ -92,17 +92,16 @@ var tabPreviews = {
 
 var tabPreviewPanelHelper = {
   opening: function (host) {
     host.panel.hidden = false;
 
     var handler = this._generateHandler(host);
     host.panel.addEventListener("popupshown", handler, false);
     host.panel.addEventListener("popuphiding", handler, false);
-    host.panel.addEventListener("popuphidden", handler, false);
 
     host._prevFocus = document.commandDispatcher.focusedElement;
   },
   _generateHandler: function (host) {
     var self = this;
     return function (event) {
       if (event.target == host.panel) {
         host.panel.removeEventListener(event.type, arguments.callee, false);
@@ -125,21 +124,16 @@ var tabPreviewPanelHelper = {
       host._prevFocus = null;
     } else
       gBrowser.selectedBrowser.focus();
 
     if (host.tabToSelect) {
       gBrowser.selectedTab = host.tabToSelect;
       host.tabToSelect = null;
     }
-  },
-  _popuphidden: function (host) {
-    // Destroy the widget in order to prevent outdated content
-    // when re-opening the panel.
-    host.panel.hidden = true;
   }
 };
 
 /**
  * Ctrl-Tab panel
  */
 var ctrlTab = {
   get panel () {

--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -129,30 +129,37 @@ XPCOMUtils.defineLazyGetter(this, "Debug
 });
 
 XPCOMUtils.defineLazyGetter(this, "Tilt", function() {
   let tmp = {};
   Cu.import("resource:///modules/devtools/Tilt.jsm", tmp);
   return new tmp.Tilt(window);
 });
 
+XPCOMUtils.defineLazyGetter(this, "Social", function() {
+  let tmp = {};
+  Cu.import("resource:///modules/Social.jsm", tmp);
+  return tmp.Social;
+});
+
 let gInitialPages = [
   "about:blank",
   "about:newtab",
   "about:home",
   "about:privatebrowsing",
   "about:sessionrestore"
 ];
 
 #include browser-addons.js
 #include browser-feeds.js
 #include browser-fullScreen.js
 #include browser-fullZoom.js
 #include browser-places.js
 #include browser-plugins.js
+#include browser-social.js
 #include browser-tabPreviews.js
 #include browser-tabview.js
 #include browser-thumbnails.js
 
 #ifdef MOZ_SERVICES_SYNC
 #include browser-syncui.js
 #endif
 
@@ -1241,16 +1248,17 @@ var gBrowserInit = {
     Services.obs.addObserver(gXPInstallObserver, "addon-install-failed", false);
     Services.obs.addObserver(gXPInstallObserver, "addon-install-complete", false);
     Services.obs.addObserver(gFormSubmitObserver, "invalidformsubmit", false);
 
     BrowserOffline.init();
     OfflineApps.init();
     IndexedDBPromptHelper.init();
     gFormSubmitObserver.init();
+    SocialUI.init();
     AddonManager.addAddonListener(AddonsMgrListener);
 
     gBrowser.addEventListener("pageshow", function(evt) { setTimeout(pageShowEventHandlers, 0, evt); }, true);
 
     // Ensure login manager is up and running.
     Cc["@mozilla.org/login-manager;1"].getService(Ci.nsILoginManager);
 
     if (mustLoadSidebar) {
@@ -1612,16 +1620,17 @@ var gBrowserInit = {
       } catch (ex) {
         Cu.reportError(ex);
       }
 
       BrowserOffline.uninit();
       OfflineApps.uninit();
       IndexedDBPromptHelper.uninit();
       AddonManager.removeAddonListener(AddonsMgrListener);
+      SocialUI.uninit();
     }
 
     // Final window teardown, do this last.
     window.XULBrowserWindow.destroy();
     window.XULBrowserWindow = null;
     window.QueryInterface(Ci.nsIInterfaceRequestor)
           .getInterface(Ci.nsIWebNavigation)
           .QueryInterface(Ci.nsIDocShellTreeItem).treeOwner
@@ -3557,16 +3566,17 @@ function BrowserToolboxCustomizeDone(aTo
   UpdateUrlbarSearchSplitterState();
   setUrlAndSearchBarWidthForConditionalForwardButton();
 
   // Update the urlbar
   if (gURLBar) {
     URLBarSetURI();
     XULBrowserWindow.asyncUpdateUI();
     PlacesStarButton.updateState();
+    SocialShareButton.updateShareState();
   }
 
   TabsInTitlebar.allowedBy("customizing-toolbars", true);
 
   // Re-enable parts of the UI we disabled during the dialog
   var menubar = document.getElementById("main-menubar");
   for (var i = 0; i < menubar.childNodes.length; ++i)
     menubar.childNodes[i].setAttribute("disabled", false);
@@ -4035,16 +4045,17 @@ var XULBrowserWindow = {
         let uri = aLocationURI;
         try {
           uri = this._uriFixup.createExposableURI(uri);
         } catch (e) {}
         URLBarSetURI(uri);
 
         // Update starring UI
         PlacesStarButton.updateState();
+        SocialShareButton.updateShareState();
       }
 
       // Show or hide browser chrome based on the whitelist
       if (this.hideChromeForLocation(location)) {
         document.documentElement.setAttribute("disablechrome", "true");
       } else {
         let ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
         if (ss.getTabValue(gBrowser.selectedTab, "appOrigin"))

--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -177,16 +177,72 @@
                 class="editBookmarkPanelBottomButton"
                 label="&editBookmark.done.label;"
                 default="true"
                 oncommand="StarUI.panel.hidePopup();"/>
 #endif
       </hbox>
     </panel>
 
+    <panel id="editSharePopup"
+           type="arrow"
+           orient="vertical"
+           ignorekeys="true"
+           hidden="true"
+           onpopupshown="SocialShareButton.panelShown(event);"
+           consumeoutsideclicks="true"
+           level="top">
+      <row id="editSharePopupHeader" align="center">
+        <vbox align="center">
+          <image id="socialUserPortrait" onclick="SocialUI.showProfile();"
+                 aria-label="&social.sharePopup.portrait.arialabel;"/>
+        </vbox>
+        <vbox id="editSharePopupText">
+          <button id="socialUserDisplayName"
+                  oncommand="SocialUI.showProfile();"/>
+          <spacer flex="1"/>
+          <label id="socialUserRecommendedText"
+                 value="&social.sharePopup.shared.label;"/>
+        </vbox>
+      </row>
+      <hbox id="editSharePopupBottomButtons" pack="end">
+#ifdef XP_UNIX
+        <button id="editSharePopupUndoButton"
+                class="editSharePopupBottomButton"
+                label="&social.sharePopup.undo.label;"
+                accesskey="&social.sharePopup.undo.accesskey;"
+                command="Social:UnsharePage"/>
+        <button id="editSharePopupOkButton"
+                class="editSharePopupBottomButton"
+                default="true"
+                autofocus="autofocus"
+                label="&social.sharePopup.ok.label;"
+                accesskey="&social.sharePopup.ok.accesskey;"
+                oncommand="SocialShareButton.dismissSharePopup();"/>
+#else
+        <button id="editSharePopupOkButton"
+                class="editSharePopupBottomButton"
+                default="true"
+                autofocus="autofocus"
+                label="&social.sharePopup.ok.label;"
+                accesskey="&social.sharePopup.ok.accesskey;"
+                oncommand="SocialShareButton.dismissSharePopup();"/>
+        <button id="editSharePopupUndoButton"
+                class="editSharePopupBottomButton"
+                label="&social.sharePopup.undo.label;"
+                accesskey="&social.sharePopup.undo.accesskey;"
+                command="Social:UnsharePage"/>
+#endif
+      </hbox>
+    </panel>
+
+    <panel id="social-notification-panel" type="arrow" hidden="true" noautofocus="true">
+      <browser id="social-notification-browser" type="content" flex="1"/>
+    </panel>
+
     <menupopup id="inspector-node-popup">
       <menuitem id="inspectorHTMLCopyInner"
                 label="&inspectorHTMLCopyInner.label;"
                 accesskey="&inspectorHTMLCopyInner.accesskey;"
                 command="Inspector:CopyInner"/>
       <menuitem id="inspectorHTMLCopyOuter"
                 label="&inspectorHTMLCopyOuter.label;"
                 accesskey="&inspectorHTMLCopyOuter.accesskey;"
@@ -459,16 +515,17 @@
                  autocompletesearch="urlinline history"
                  autocompletesearchparam="enable-actions"
                  autocompletepopup="PopupAutoCompleteRichResult"
                  completeselectedindex="true"
                  tabscrolling="true"
                  showcommentcolumn="true"
                  showimagecolumn="true"
                  enablehistory="true"
+                 maxrows="6"
                  newlines="stripsurroundingwhitespace"
                  oninput="gBrowser.userTypedValue = this.value;"
                  ontextentered="this.handleCommand(param);"
                  ontextreverted="return this.handleRevert();"
                  pageproxystate="invalid"
                  onfocus="document.getElementById('identity-box').style.MozUserFocus= 'normal'"
                  onblur="setTimeout(function() document.getElementById('identity-box').style.MozUserFocus = '', 0);">
           <box id="notification-popup-box" hidden="true" align="center">
@@ -502,16 +559,22 @@
           </box>
           <hbox id="urlbar-icons">
             <image id="page-report-button"
                    class="urlbar-icon"
                    hidden="true"
                    tooltiptext="&pageReportIcon.tooltip;"
                    onclick="gPopupBlockerObserver.onReportButtonClick(event);"/>
 
+            <label id="share-button-status" collapsed="true" role="status"/>
+            <image id="share-button"
+                   class="urlbar-icon"
+                   hidden="true"
+                   onclick="SocialShareButton.onClick(event);"/>
+
             <image id="star-button"
                    class="urlbar-icon"
                    onclick="PlacesStarButton.onClick(event);"/>
             <image id="go-button"
                    class="urlbar-icon"
                    tooltiptext="&goEndCap.tooltip;"
                    onclick="gURLBar.handleCommand(event);"/>
           </hbox>
@@ -553,16 +616,55 @@
                      label="&homeButton.label;"
                      ondragover="homeButtonObserver.onDragOver(event)"
                      ondragenter="homeButtonObserver.onDragOver(event)"
                      ondrop="homeButtonObserver.onDrop(event)"
                      ondragexit="homeButtonObserver.onDragExit(event)"
                      onclick="BrowserGoHome(event);"
                      aboutHomeOverrideTooltip="&abouthome.pageTitle;"/>
 
+      <toolbaritem id="social-toolbar-button"
+                   class="toolbarbutton-1 chromeclass-toolbar-additional"
+                   removable="false"
+                   title="&socialToolbar.title;"
+                   hidden="true">
+        <hbox id="social-toolbar-button-box" class="social-statusarea-container">
+          <button id="social-provider-image" type="menu">
+            <menupopup id="social-statusarea-popup">
+              <hbox id="social-statusarea-user" pack="left" align="center">
+                <image id="social-statusarea-user-portrait"/>
+                <vbox>
+                  <label id="social-statusarea-notloggedin"
+                         value="&social.notLoggedIn.label;"/>
+                  <button id="social-statusarea-username"
+                          oncommand="SocialUI.showProfile(); document.getElementById('social-statusarea-popup').hidePopup();"/>
+                </vbox>
+              </hbox>
+            </menupopup>
+          </button>
+          <hbox id="social-status-iconbox" flex="1">
+            <box class="social-notification-icon-container" collapsed="true"
+                     onclick="SocialToolbar.showAmbientPopup(this);">
+              <image class="social-notification-icon-image"/>
+              <box class="social-notification-icon-counter" collapsed="true"/>
+            </box>
+            <box class="social-notification-icon-container" collapsed="true"
+                     onclick="SocialToolbar.showAmbientPopup(this);">
+              <image class="social-notification-icon-image"/>
+              <box class="social-notification-icon-counter" collapsed="true"/>
+            </box>
+            <box class="social-notification-icon-container" collapsed="true"
+                     onclick="SocialToolbar.showAmbientPopup(this);">
+              <image class="social-notification-icon-image"/>
+              <box class="social-notification-icon-counter" collapsed="true"/>
+            </box>
+          </hbox>
+        </hbox>
+      </toolbaritem>
+
       <toolbaritem id="bookmarks-menu-button-container"
                    class="chromeclass-toolbar-additional"
                    removable="true"
                    title="&bookmarksMenuButton.label;">
         <toolbarbutton id="bookmarks-menu-button"
                        type="menu"
                        class="toolbarbutton-1"
                        label="&bookmarksMenuButton.label;"

--- a/browser/base/content/newtab/drag.js
+++ b/browser/base/content/newtab/drag.js
@@ -102,22 +102,27 @@ let gDrag = {
   },
 
   /**
    * Checks whether we're responsible for a given drag event.
    * @param aEvent The drag event to check.
    * @return Whether we should handle this drag and drop operation.
    */
   isValid: function Drag_isValid(aEvent) {
-    let dt = aEvent.dataTransfer;
-    let mimeType = "text/x-moz-url";
+    let link = gDragDataHelper.getLinkFromDragEvent(aEvent);
 
     // Check that the drag data is non-empty.
     // Can happen when dragging places folders.
-    return dt && dt.types.contains(mimeType) && dt.getData(mimeType);
+    if (!link || !link.url) {
+      return false;
+    }
+
+    // Check that we're not accepting URLs which would inherit the caller's
+    // principal (such as javascript: or data:).
+    return gLinkChecker.checkLoadURI(link.url);
   },
 
   /**
    * Initializes the drag data for the current drag operation.
    * @param aSite The site that's being dragged.
    * @param aEvent The 'dragstart' event.
    */
   _setDragData: function Drag_setDragData(aSite, aEvent) {