--- a/CLOBBER
+++ b/CLOBBER
@@ -17,9 +17,9 @@
 #
 # Modifying this file will now automatically clobber the buildbot machines \o/
 #
 
 # Are you updating CLOBBER because you think it's needed for your WebIDL
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Bug 1288460 requires another clobber due to bug 1298779.
+Bug 1302429 to fix also bustage.

--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1502,8 +1502,19 @@ pref("extensions.pocket.enabled", true);
 pref("signon.schemeUpgrades", true);
 
 // Enable the "Simplify Page" feature in Print Preview
 pref("print.use_simplify_page", true);
 
 // Space separated list of URLS that are allowed to send objects (instead of
 // only strings) through webchannels. This list is duplicated in mobile/android/app/mobile.js
 pref("webchannel.allowObject.urlWhitelist", "https://accounts.firefox.com https://content.cdn.mozilla.net https://input.mozilla.org https://support.mozilla.org https://install.mozilla.org");
+
+// Whether or not the browser should scan for unsubmitted
+// crash reports, and then show a notification for submitting
+// those reports.
+#ifdef RELEASE_BUILD
+pref("browser.crashReports.unsubmittedCheck.enabled", false);
+#else
+pref("browser.crashReports.unsubmittedCheck.enabled", true);
+#endif
+
+pref("browser.crashReports.unsubmittedCheck.autoSubmit", false);
\ No newline at end of file

--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -772,23 +772,16 @@ html|*#fullscreen-exit-button {
 #addon-progress-notification {
   -moz-binding: url("chrome://browser/content/urlbarBindings.xml#addon-progress-notification");
 }
 
 #click-to-play-plugins-notification {
   -moz-binding: url("chrome://browser/content/urlbarBindings.xml#click-to-play-plugins-notification");
 }
 
-#login-fill-notification {
-  -moz-binding: url("chrome://browser/content/urlbarBindings.xml#login-fill-notification");
-}
-
-.login-fill-item {
-  -moz-binding: url("chrome://passwordmgr/content/login.xml#login");
-}
 
 .plugin-popupnotification-centeritem {
   -moz-binding: url("chrome://browser/content/urlbarBindings.xml#plugin-popupnotification-center-item");
 }
 
 browser[tabmodalPromptShowing] {
   -moz-user-focus: none !important;
 }
@@ -1180,20 +1173,16 @@ toolbarpaletteitem[place="palette"][hidd
 }
 
 /* Combined context-menu items */
 #context-navigation > .menuitem-iconic > .menu-iconic-text,
 #context-navigation > .menuitem-iconic > .menu-accel-container {
   display: none;
 }
 
-#login-fill-doorhanger:not([inDetailView]) > #login-fill-clickcapturer {
-  pointer-events: none;
-}
-
 .popup-notification-invalid-input {
   box-shadow: 0 0 1.5px 1px red;
 }
 
 .popup-notification-invalid-input[focused] {
   box-shadow: 0 0 2px 2px rgba(255,0,0,0.4);
 }
 

--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -713,18 +713,16 @@
                   <image id="default-notification-icon" class="notification-anchor-icon" role="button"
                          tooltiptext="&urlbar.defaultNotificationAnchor.tooltip;"/>
                   <image id="geo-notification-icon" class="notification-anchor-icon geo-icon" role="button"
                          tooltiptext="&urlbar.geolocationNotificationAnchor.tooltip;"/>
                   <image id="addons-notification-icon" class="notification-anchor-icon install-icon" role="button"
                          tooltiptext="&urlbar.addonsNotificationAnchor.tooltip;"/>
                   <image id="indexedDB-notification-icon" class="notification-anchor-icon indexedDB-icon" role="button"
                          tooltiptext="&urlbar.indexedDBNotificationAnchor.tooltip;"/>
-                  <image id="login-fill-notification-icon" class="notification-anchor-icon login-icon" role="button"
-                         tooltiptext="&urlbar.loginFillNotificationAnchor.tooltip;"/>
                   <image id="password-notification-icon" class="notification-anchor-icon login-icon" role="button"
                          tooltiptext="&urlbar.passwordNotificationAnchor.tooltip;"/>
                   <image id="plugins-notification-icon" class="notification-anchor-icon plugin-icon" role="button"
                          tooltiptext="&urlbar.pluginsNotificationAnchor.tooltip;"/>
                   <image id="web-notifications-notification-icon" class="notification-anchor-icon desktop-notification-icon" role="button"
                          tooltiptext="&urlbar.webNotificationAnchor.tooltip;"/>
                   <image id="webRTC-shareDevices-notification-icon" class="notification-anchor-icon camera-icon" role="button"
                          tooltiptext="&urlbar.webRTCShareDevicesNotificationAnchor.tooltip;"/>

--- a/browser/base/content/popup-notifications.inc
+++ b/browser/base/content/popup-notifications.inc
@@ -47,32 +47,16 @@
     <popupnotification id="password-notification" hidden="true">
       <popupnotificationcontent orient="vertical">
         <textbox id="password-notification-username"/>
         <textbox id="password-notification-password" type="password" show-content=""/>
         <checkbox id="password-notification-visibilityToggle" hidden="true"/>
       </popupnotificationcontent>
     </popupnotification>
 
-    <stack id="login-fill-doorhanger" hidden="true">
-      <vbox id="login-fill-mainview">
-        <description id="login-fill-testing"
-                     value="Thanks for testing the login fill doorhanger!"/>
-        <textbox id="login-fill-filter"/>
-        <richlistbox id="login-fill-list"/>
-      </vbox>
-      <vbox id="login-fill-clickcapturer"/>
-      <vbox id="login-fill-details">
-        <textbox id="login-fill-username" readonly="true"/>
-        <textbox id="login-fill-password" type="password" disabled="true"/>
-        <hbox>
-          <button id="login-fill-use" label="Use in form"/>
-        </hbox>
-      </vbox>
-    </stack>
 
     <popupnotification id="addon-progress-notification" hidden="true">
       <popupnotificationcontent orient="vertical">
         <progressmeter id="addon-progress-notification-progressmeter"/>
         <label id="addon-progress-notification-progresstext" crop="end"/>
       </popupnotificationcontent>
       <button id="addon-progress-cancel"
               oncommand="this.parentNode.cancel();"/>

--- a/browser/base/content/urlbarBindings.xml
+++ b/browser/base/content/urlbarBindings.xml
@@ -2473,26 +2473,16 @@ file, You can obtain one at http://mozil
     </implementation>
     <handlers>
       <!-- The _accept method checks for .defaultPrevented so that if focus is in a button,
            enter activates the button and not this default action -->
       <handler event="keypress" keycode="VK_RETURN" group="system" action="this._accept(event);"/>
     </handlers>
   </binding>
 
-  <!-- This is the XBL notification definition for the login fill doorhanger,
-       which is empty because the actual panel is not implemented inside an XBL
-       binding, but made of elements added to the notification panel. This
-       allows accessing the full structure while the panel is hidden. -->
-  <binding id="login-fill-notification" extends="chrome://global/content/bindings/notification.xml#popup-notification">
-    <content>
-      <children/>
-    </content>
-  </binding>
-
   <binding id="splitmenu">
     <content>
       <xul:hbox anonid="menuitem" flex="1"
                 class="splitmenu-menuitem"
                 xbl:inherits="iconic,label,disabled,onclick=oncommand,_moz-menuactive=active"/>
       <xul:menu anonid="menu" class="splitmenu-menu"
                 xbl:inherits="disabled,_moz-menuactive=active"
                 oncommand="event.stopPropagation();">

--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -66,16 +66,18 @@ XPCOMUtils.defineLazyServiceGetter(this,
   ["WebChannel", "resource://gre/modules/WebChannel.jsm"],
   ["WindowsRegistry", "resource://gre/modules/WindowsRegistry.jsm"],
   ["webrtcUI", "resource:///modules/webrtcUI.jsm"],
 ].forEach(([name, resource]) => XPCOMUtils.defineLazyModuleGetter(this, name, resource));
 
 if (AppConstants.MOZ_CRASHREPORTER) {
   XPCOMUtils.defineLazyModuleGetter(this, "PluginCrashReporter",
                                     "resource:///modules/ContentCrashHandlers.jsm");
+  XPCOMUtils.defineLazyModuleGetter(this, "UnsubmittedCrashHandler",
+                                    "resource:///modules/ContentCrashHandlers.jsm");
   XPCOMUtils.defineLazyModuleGetter(this, "CrashSubmit",
                                     "resource://gre/modules/CrashSubmit.jsm");
 }
 
 XPCOMUtils.defineLazyGetter(this, "gBrandBundle", function() {
   return Services.strings.createBundle('chrome://branding/locale/brand.properties');
 });
 
@@ -709,16 +711,17 @@ BrowserGlue.prototype = {
         iconURL: "resource:///chrome/browser/content/browser/defaultthemes/devedition.icon.png",
         author: vendorShortName,
       });
     }
 
     TabCrashHandler.init();
     if (AppConstants.MOZ_CRASHREPORTER) {
       PluginCrashReporter.init();
+      UnsubmittedCrashHandler.init();
     }
 
     Services.obs.notifyObservers(null, "browser-ui-startup-complete", "");
   },
 
   _checkForOldBuildUpdates: function () {
     // check for update if our build is old
     if (AppConstants.MOZ_UPDATER &&
@@ -739,74 +742,16 @@ BrowserGlue.prototype = {
       let acceptableAge = Services.prefs.getIntPref("app.update.checkInstallTime.days") * millisecondsIn24Hours;
 
       if (buildDate + acceptableAge < today) {
         Cc["@mozilla.org/updates/update-service;1"].getService(Ci.nsIApplicationUpdateService).checkForBackgroundUpdates();
       }
     }
   },
 
-  checkForPendingCrashReports: function() {
-    // We don't process crash reports older than 28 days, so don't bother submitting them
-    const PENDING_CRASH_REPORT_DAYS = 28;
-    if (AppConstants.MOZ_CRASHREPORTER) {
-      let dateLimit = new Date();
-      dateLimit.setDate(dateLimit.getDate() - PENDING_CRASH_REPORT_DAYS);
-      CrashSubmit.pendingIDsAsync(dateLimit).then(
-        function onSuccess(ids) {
-          let count = ids.length;
-          if (count) {
-            let win = RecentWindow.getMostRecentBrowserWindow();
-            if (!win) {
-              return;
-            }
-            let nb =  win.document.getElementById("global-notificationbox");
-            let notification = nb.getNotificationWithValue("pending-crash-reports");
-            if (notification) {
-              return;
-            }
-            let buttons = [
-              {
-                label: win.gNavigatorBundle.getString("pendingCrashReports.submitAll"),
-                callback: function() {
-                  ids.forEach(function(id) {
-                    CrashSubmit.submit(id, {extraExtraKeyVals: {"SubmittedFromInfobar": true}});
-                  });
-                }
-              },
-              {
-                label: win.gNavigatorBundle.getString("pendingCrashReports.ignoreAll"),
-                callback: function() {
-                  ids.forEach(function(id) {
-                    CrashSubmit.ignore(id);
-                  });
-                }
-              },
-              {
-                label: win.gNavigatorBundle.getString("pendingCrashReports.viewAll"),
-                callback: function() {
-                  win.openUILinkIn("about:crashes", "tab");
-                  return true;
-                }
-              }
-            ];
-            nb.appendNotification(PluralForm.get(count,
-                                                 win.gNavigatorBundle.getString("pendingCrashReports.label")).replace("#1", count),
-                                  "pending-crash-reports",
-                                  "chrome://browser/skin/tab-crashed.svg",
-                                  nb.PRIORITY_INFO_HIGH, buttons);
-          }
-        },
-        function onError(err) {
-          Cu.reportError(err);
-        }
-      );
-    }
-  },
-
   _onSafeModeRestart: function BG_onSafeModeRestart() {
     // prompt the user to confirm
     let strings = gBrowserBundle;
     let promptTitle = strings.GetStringFromName("safeModeRestartPromptTitle");
     let promptMessage = strings.GetStringFromName("safeModeRestartPromptMessage");
     let restartText = strings.GetStringFromName("safeModeRestartButton");
     let buttonFlags = (Services.prompt.BUTTON_POS_0 *
                        Services.prompt.BUTTON_TITLE_IS_STRING) +
@@ -1065,20 +1010,16 @@ BrowserGlue.prototype = {
         if (removalSuccessful && uninstalledValue == "True") {
           this._resetProfileNotification("uninstall");
         }
       }
     }
 
     this._checkForOldBuildUpdates();
 
-    if (!AppConstants.RELEASE_BUILD) {
-      this.checkForPendingCrashReports();
-    }
-
     CaptivePortalWatcher.init();
 
     AutoCompletePopup.init();
 
     this._firstWindowTelemetry(aWindow);
     this._firstWindowLoaded();
   },
 

--- a/browser/components/preferences/in-content/advanced.js
+++ b/browser/components/preferences/in-content/advanced.js
@@ -55,20 +55,17 @@ var gAdvancedPane = {
     setEventListener("layers.acceleration.disabled", "change",
                      gAdvancedPane.updateHardwareAcceleration);
     setEventListener("advancedPrefs", "select",
                      gAdvancedPane.tabSelectionChanged);
     if (AppConstants.MOZ_TELEMETRY_REPORTING) {
       setEventListener("submitHealthReportBox", "command",
                        gAdvancedPane.updateSubmitHealthReport);
     }
-    if (AppConstants.MOZ_CRASHREPORTER) {
-      setEventListener("submitCrashesBox", "command",
-                       gAdvancedPane.updateSubmitCrashes);
-    }
+
     setEventListener("connectionSettings", "command",
                      gAdvancedPane.showConnections);
     setEventListener("clearCacheButton", "command",
                      gAdvancedPane.clearCache);
     setEventListener("clearOfflineAppCacheButton", "command",
                      gAdvancedPane.clearOfflineAppCache);
     setEventListener("offlineNotifyExceptions", "command",
                      gAdvancedPane.showOfflineExceptions);
@@ -238,38 +235,16 @@ var gAdvancedPane = {
 
   /**
    *
    */
   initSubmitCrashes: function ()
   {
     this._setupLearnMoreLink("toolkit.crashreporter.infoURL",
                              "crashReporterLearnMore");
-
-    var checkbox = document.getElementById("submitCrashesBox");
-    try {
-      var cr = Components.classes["@mozilla.org/toolkit/crash-reporter;1"].
-               getService(Components.interfaces.nsICrashReporter);
-      checkbox.checked = cr.submitReports;
-    } catch (e) {
-      checkbox.style.display = "none";
-    }
-  },
-
-  /**
-   *
-   */
-  updateSubmitCrashes: function ()
-  {
-    var checkbox = document.getElementById("submitCrashesBox");
-    try {
-      var cr = Components.classes["@mozilla.org/toolkit/crash-reporter;1"].
-               getService(Components.interfaces.nsICrashReporter);
-      cr.submitReports = checkbox.checked;
-    } catch (e) { }
   },
 
   /**
    * The preference/checkbox is configured in XUL.
    *
    * In all cases, set up the Learn More link sanely.
    */
   initTelemetry: function ()

--- a/browser/components/preferences/in-content/advanced.xul
+++ b/browser/components/preferences/in-content/advanced.xul
@@ -49,16 +49,23 @@
               type="int"/>
 
 #ifdef MOZ_TELEMETRY_REPORTING
   <preference id="toolkit.telemetry.enabled"
               name="toolkit.telemetry.enabled"
               type="bool"/>
 #endif
 
+  <!-- Data Choices tab -->
+#ifdef MOZ_CRASHREPORTER
+  <preference id="browser.crashReports.unsubmittedCheck.autoSubmit"
+              name="browser.crashReports.unsubmittedCheck.autoSubmit"
+              type="bool"/>
+#endif
+
   <!-- Network tab -->
   <preference id="browser.cache.disk.capacity"
               name="browser.cache.disk.capacity"
               type="int"/>
   <preference id="browser.offline-apps.notify"
               name="browser.offline-apps.notify"
               type="bool"/>
 
@@ -224,21 +231,23 @@
             </groupbox>
           </hbox>
         </vbox>
       </groupbox>
 #endif
 #ifdef MOZ_CRASHREPORTER
       <groupbox>
         <caption>
-          <checkbox id="submitCrashesBox" label="&enableCrashReporter.label;"
-                    accesskey="&enableCrashReporter.accesskey;"/>
+          <checkbox id="automaticallySubmitCrashesBox"
+                    preference="browser.crashReports.unsubmittedCheck.autoSubmit"
+                    label="&alwaysSubmitCrashReports.label;"
+                    accesskey="&alwaysSubmitCrashReports.accesskey;"/>
         </caption>
         <hbox class="indent">
-          <label flex="1">&crashReporterDesc.label;</label>
+          <label flex="1">&crashReporterDesc2.label;</label>
           <spacer flex="10"/>
           <label id="crashReporterLearnMore"
                  class="text-link">&crashReporterLearnMore.label;</label>
         </hbox>
       </groupbox>
 #endif
     </tabpanel>
 #endif

--- a/browser/config/tooltool-manifests/win32/releng.manifest
+++ b/browser/config/tooltool-manifests/win32/releng.manifest
@@ -24,16 +24,16 @@
 {
 "size": 167175,
 "digest": "0b71a936edf5bd70cf274aaa5d7abc8f77fe8e7b5593a208f805cc9436fac646b9c4f0b43c2b10de63ff3da671497d35536077ecbc72dba7f8159a38b580f831",
 "algorithm": "sha512",
 "filename": "sccache.tar.bz2",
 "unpack": true
 },
 {
-"version": "Visual Studio 2015 Update 2 / SDK 10.0.10586.0/212",
-"size": 332442800,
-"digest": "995394a4a515c7cb0f8595f26f5395361a638870dd0bbfcc22193fe1d98a0c47126057d5999cc494f3f3eac5cb49160e79757c468f83ee5797298e286ef6252c",
+"version": "Visual Studio 2015 Update 3 14.0.25425.01 / SDK 10.0.14393.0",
+"size": 326656969,
+"digest": "babc414ffc0457d27f5a1ed24a8e4873afbe2f1c1a4075469a27c005e1babc3b2a788f643f825efedff95b79686664c67ec4340ed535487168a3482e68559bc7",
 "algorithm": "sha512",
-"filename": "vs2015u2.zip",
+"filename": "vs2015u3.zip",
 "unpack": true
 }
 ]

--- a/browser/config/tooltool-manifests/win64/releng.manifest
+++ b/browser/config/tooltool-manifests/win64/releng.manifest
@@ -25,16 +25,16 @@
 {
 "size": 167175,
 "digest": "0b71a936edf5bd70cf274aaa5d7abc8f77fe8e7b5593a208f805cc9436fac646b9c4f0b43c2b10de63ff3da671497d35536077ecbc72dba7f8159a38b580f831",
 "algorithm": "sha512",
 "filename": "sccache.tar.bz2",
 "unpack": true
 },
 {
-"version": "Visual Studio 2015 Update 2 / SDK 10.0.10586.0/212",
-"size": 332442800,
-"digest": "995394a4a515c7cb0f8595f26f5395361a638870dd0bbfcc22193fe1d98a0c47126057d5999cc494f3f3eac5cb49160e79757c468f83ee5797298e286ef6252c",
+"version": "Visual Studio 2015 Update 3 14.0.25425.01 / SDK 10.0.14393.0",
+"size": 326656969,
+"digest": "babc414ffc0457d27f5a1ed24a8e4873afbe2f1c1a4075469a27c005e1babc3b2a788f643f825efedff95b79686664c67ec4340ed535487168a3482e68559bc7",
 "algorithm": "sha512",
-"filename": "vs2015u2.zip",
+"filename": "vs2015u3.zip",
 "unpack": true
 }
 ]

--- a/browser/locales/en-US/chrome/browser/browser.dtd
+++ b/browser/locales/en-US/chrome/browser/browser.dtd
@@ -206,17 +206,16 @@ These should match what Safari and other
 <!ENTITY printButton.tooltip          "Print this page">
 
 <!ENTITY urlbar.viewSiteInfo.label                      "View site information">
 
 <!ENTITY urlbar.defaultNotificationAnchor.tooltip         "Open message panel">
 <!ENTITY urlbar.geolocationNotificationAnchor.tooltip     "Open location request panel">
 <!ENTITY urlbar.addonsNotificationAnchor.tooltip          "Open add-on installation message panel">
 <!ENTITY urlbar.indexedDBNotificationAnchor.tooltip       "Open offline storage message panel">
-<!ENTITY urlbar.loginFillNotificationAnchor.tooltip       "Manage your login information">
 <!ENTITY urlbar.passwordNotificationAnchor.tooltip        "Open save password message panel">
 <!ENTITY urlbar.pluginsNotificationAnchor.tooltip         "Manage plug-in use">
 <!ENTITY urlbar.webNotificationAnchor.tooltip             "Change whether you can receive notifications from the site">
 
 <!ENTITY urlbar.webRTCShareDevicesNotificationAnchor.tooltip      "Manage sharing your camera and/or microphone with the site">
 <!ENTITY urlbar.webRTCShareMicrophoneNotificationAnchor.tooltip   "Manage sharing your microphone with the site">
 <!ENTITY urlbar.webRTCShareScreenNotificationAnchor.tooltip       "Manage sharing your windows or screen with the site">
 

--- a/browser/locales/en-US/chrome/browser/browser.properties
+++ b/browser/locales/en-US/chrome/browser/browser.properties
@@ -725,20 +725,20 @@ certErrorDetailsCertChain.label = Certif
 # LOCALIZATION NOTE (tabgroups.migration.anonGroup):
 # %S is the group number/ID
 tabgroups.migration.anonGroup = Group %S
 tabgroups.migration.tabGroupBookmarkFolderName = Bookmarked Tab Groups
 
 # LOCALIZATION NOTE (pendingCrashReports.label): Semi-colon list of plural forms
 # See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
 # #1 is the number of pending crash reports
-pendingCrashReports.label = You have an unsubmitted crash report;You have #1 unsubmitted crash reports
+pendingCrashReports2.label = You have an unsent crash report;You have #1 unsent crash reports
 pendingCrashReports.viewAll = View
-pendingCrashReports.submitAll = Submit
-pendingCrashReports.ignoreAll = Ignore
+pendingCrashReports.send = Send
+pendingCrashReports.alwaysSend = Always Send
 
 decoder.noCodecs.button = Learn how
 decoder.noCodecs.accesskey = L
 decoder.noCodecs.message = To play video, you may need to install Microsoft’s Media Feature Pack.
 decoder.noCodecsVista.message = To play video, you may need to install Microsoft’s Platform Update Supplement for Windows Vista.
 decoder.noCodecsXP.message = To play video, you may need to enable Adobe’s Primetime Content Decryption Module.
 decoder.noCodecsLinux.message = To play video, you may need to install the required video codecs.
 decoder.noHWAcceleration.message = To improve video quality, you may need to install Microsoft’s Media Feature Pack.

--- a/browser/locales/en-US/chrome/browser/preferences/advanced.dtd
+++ b/browser/locales/en-US/chrome/browser/preferences/advanced.dtd
@@ -35,20 +35,20 @@
 <!ENTITY enableHealthReport.accesskey    "R">
 <!ENTITY healthReportLearnMore.label     "Learn More">
 
 <!ENTITY telemetryDesc.label             "Shares performance, usage, hardware and customization data about your browser with &vendorShortName; to help us make &brandShortName; better">
 <!ENTITY enableTelemetryData.label       "Share additional data (i.e., Telemetry)">
 <!ENTITY enableTelemetryData.accesskey   "T">
 <!ENTITY telemetryLearnMore.label        "Learn More">
 
-<!ENTITY crashReporterDesc.label         "&brandShortName; submits crash reports to help &vendorShortName; make your browser more stable and secure">
-<!ENTITY enableCrashReporter.label       "Enable Crash Reporter">
-<!ENTITY enableCrashReporter.accesskey   "C">
-<!ENTITY crashReporterLearnMore.label    "Learn More">
+<!ENTITY crashReporterDesc2.label         "Crash reports help &vendorShortName; fix problems and make your browser more stable and secure">
+<!ENTITY alwaysSubmitCrashReports.label   "Allow &brandShortName; to send backlogged crash reports on your behalf">
+<!ENTITY alwaysSubmitCrashReports.accesskey "c">
+<!ENTITY crashReporterLearnMore.label     "Learn More">
 
 <!ENTITY networkTab.label                "Network">
 
 <!ENTITY connection.label                "Connection">
 
 <!ENTITY connectionDesc.label            "Configure how &brandShortName; connects to the Internet">
 <!ENTITY connectionSettings.label        "Settings…">
 <!ENTITY connectionSettings.accesskey    "e">

--- a/browser/modules/ContentCrashHandlers.jsm
+++ b/browser/modules/ContentCrashHandlers.jsm
@@ -3,29 +3,46 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
-this.EXPORTED_SYMBOLS = [ "TabCrashHandler", "PluginCrashReporter" ];
+this.EXPORTED_SYMBOLS = [ "TabCrashHandler",
+                          "PluginCrashReporter",
+                          "UnsubmittedCrashHandler" ];
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "CrashSubmit",
   "resource://gre/modules/CrashSubmit.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "AppConstants",
   "resource://gre/modules/AppConstants.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "RemotePages",
   "resource://gre/modules/RemotePageManager.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "SessionStore",
   "resource:///modules/sessionstore/SessionStore.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+  "resource://gre/modules/Task.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "RecentWindow",
+  "resource:///modules/RecentWindow.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PluralForm",
+  "resource://gre/modules/PluralForm.jsm");
+
+XPCOMUtils.defineLazyGetter(this, "gNavigatorBundle", function() {
+  const url = "chrome://browser/locale/browser.properties";
+  return Services.strings.createBundle(url);
+});
+
+// We don't process crash reports older than 28 days, so don't bother
+// submitting them
+const PENDING_CRASH_REPORT_DAYS = 28;
 
 this.TabCrashHandler = {
   _crashedTabCount: 0,
 
   get prefs() {
     delete this.prefs;
     return this.prefs = Services.prefs.getBranch("browser.tabs.crashReporting.");
   },
@@ -314,16 +331,214 @@ this.TabCrashHandler = {
     if (!this.childMap) {
       return null;
     }
 
     return this.childMap.get(this.browserMap.get(browser.permanentKey));
   },
 }
 
+/**
+ * This component is responsible for scanning the pending
+ * crash report directory for reports, and (if enabled), to
+ * prompt the user to submit those reports. It might also
+ * submit those reports automatically without prompting if
+ * the user has opted in.
+ */
+this.UnsubmittedCrashHandler = {
+  init() {
+    if (this.initialized) {
+      return;
+    }
+
+    this.initialized = true;
+
+    let pref = "browser.crashReports.unsubmittedCheck.enabled";
+    let shouldCheck = Services.prefs.getBoolPref(pref);
+
+    if (shouldCheck) {
+      Services.obs.addObserver(this, "browser-delayed-startup-finished",
+                               false);
+    }
+  },
+
+  observe(subject, topic, data) {
+    if (topic != "browser-delayed-startup-finished") {
+      return;
+    }
+
+    Services.obs.removeObserver(this, topic);
+    this.checkForUnsubmittedCrashReports();
+  },
+
+  /**
+   * Scans the profile directory for unsubmitted crash reports
+   * within the past PENDING_CRASH_REPORT_DAYS days. If it
+   * finds any, it will, if necessary, attempt to open a notification
+   * bar to prompt the user to submit them.
+   *
+   * @returns Promise
+   *          Resolves after it tries to append a notification on
+   *          the most recent browser window. If a notification
+   *          cannot be shown, will resolve anyways.
+   */
+  checkForUnsubmittedCrashReports: Task.async(function*() {
+    let dateLimit = new Date();
+    dateLimit.setDate(dateLimit.getDate() - PENDING_CRASH_REPORT_DAYS);
+
+    let reportIDs = [];
+    try {
+      reportIDs = yield CrashSubmit.pendingIDsAsync(dateLimit);
+    } catch (e) {
+      Cu.reportError(e);
+      return;
+    }
+
+    if (reportIDs.length) {
+      if (CrashNotificationBar.autoSubmit) {
+        CrashNotificationBar.submitReports(reportIDs);
+      } else {
+        this.showPendingSubmissionsNotification(reportIDs);
+      }
+    }
+  }),
+
+  /**
+   * Given an array of unsubmitted crash report IDs, try to open
+   * up a notification asking the user to submit them.
+   *
+   * @param reportIDs (Array<string>)
+   *        The Array of report IDs to offer the user to send.
+   */
+  showPendingSubmissionsNotification(reportIDs) {
+    let count = reportIDs.length;
+    if (!count) {
+      return;
+    }
+
+    let messageTemplate =
+      gNavigatorBundle.GetStringFromName("pendingCrashReports2.label");
+
+    let message = PluralForm.get(count, messageTemplate).replace("#1", count);
+
+    CrashNotificationBar.show({
+      notificationID: "pending-crash-reports",
+      message,
+      reportIDs,
+    });
+  },
+};
+
+this.CrashNotificationBar = {
+  /**
+   * Attempts to show a notification bar to the user in the most
+   * recent browser window asking them to submit some crash report
+   * IDs. If a notification cannot be shown (for example, there
+   * is no browser window), this method exits silently.
+   *
+   * The notification will allow the user to submit their crash
+   * reports. If the user dismissed the notification, the crash
+   * reports will be marked to be ignored (though they can
+   * still be manually submitted via about:crashes).
+   *
+   * @param JS Object
+   *        An Object with the following properties:
+   *
+   *        notificationID (string)
+   *          The ID for the notification to be opened.
+   *
+   *        message (string)
+   *          The message to be displayed in the notification.
+   *
+   *        reportIDs (Array<string>)
+   *          The array of report IDs to offer to the user.
+   */
+  show({ notificationID, message, reportIDs }) {
+    let chromeWin = RecentWindow.getMostRecentBrowserWindow();
+    if (!chromeWin) {
+      // Can't show a notification in this case. We'll hopefully
+      // get another opportunity to have the user submit their
+      // crash reports later.
+      return;
+    }
+
+    let nb =  chromeWin.document.getElementById("global-notificationbox");
+    let notification = nb.getNotificationWithValue(notificationID);
+    if (notification) {
+      return;
+    }
+
+    let buttons = [{
+      label: gNavigatorBundle.GetStringFromName("pendingCrashReports.send"),
+      callback: () => {
+        this.submitReports(reportIDs);
+      },
+    },
+    {
+      label: gNavigatorBundle.GetStringFromName("pendingCrashReports.alwaysSend"),
+      callback: () => {
+        this.autoSubmit = true;
+        this.submitReports(reportIDs);
+      },
+    },
+    {
+      label: gNavigatorBundle.GetStringFromName("pendingCrashReports.viewAll"),
+      callback: function() {
+        chromeWin.openUILinkIn("about:crashes", "tab");
+        return true;
+      },
+    }];
+
+    let eventCallback = (eventType) => {
+      if (eventType == "dismissed") {
+        // The user intentionally dismissed the notification,
+        // which we interpret as meaning that they don't care
+        // to submit the reports. We'll ignore these particular
+        // reports going forward.
+        reportIDs.forEach(function(reportID) {
+          CrashSubmit.ignore(reportID);
+        });
+      }
+    };
+
+    nb.appendNotification(message, notificationID,
+                          "chrome://browser/skin/tab-crashed.svg",
+                          nb.PRIORITY_INFO_HIGH, buttons,
+                          eventCallback);
+  },
+
+  get autoSubmit() {
+    return Services.prefs
+                   .getBoolPref("browser.crashReports.unsubmittedCheck.autoSubmit");
+  },
+
+  set autoSubmit(val) {
+    Services.prefs.setBoolPref("browser.crashReports.unsubmittedCheck.autoSubmit",
+                               val);
+  },
+
+  /**
+   * Attempt to submit reports to the crash report server. Each
+   * report will have the "SubmittedFromInfobar" extra key set
+   * to true.
+   *
+   * @param reportIDs (Array<string>)
+   *        The array of reportIDs to submit.
+   */
+  submitReports(reportIDs) {
+    for (let reportID of reportIDs) {
+      CrashSubmit.submit(reportID, {
+        extraExtraKeyVals: {
+          "SubmittedFromInfobar": true,
+        },
+      });
+    }
+  },
+};
+
 this.PluginCrashReporter = {
   /**
    * Makes the PluginCrashReporter ready to hear about and
    * submit crash reports.
    */
   init() {
     if (this.initialized) {
       return;

--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -1740,17 +1740,16 @@ toolbarbutton.chevron > .toolbarbutton-i
 %include ../../../devtools/client/themes/responsivedesign.inc.css
 %include ../../../devtools/client/themes/commandline.inc.css
 %include ../shared/plugin-doorhanger.inc.css
 
 notification.pluginVulnerable > .notification-inner > .messageCloseButton:not(:hover) {
   background-image: -moz-image-rect(url("chrome://global/skin/icons/close.svg"), 0, 80, 16, 64);
 }
 
-%include ../shared/login-doorhanger.inc.css
 
 %include downloads/indicator.css
 
 .gcli-panel {
   padding: 0;
 }
 
 .gclitoolbar-input-node > .textbox-input-box > html|*.textbox-input::-moz-selection {

--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -3150,17 +3150,16 @@ menulist.translate-infobar-element > .me
   margin-left: 1em;
 }
 
 %include ../shared/fullscreen/warning.inc.css
 %include ../shared/ctrlTab.inc.css
 %include ../../../devtools/client/themes/responsivedesign.inc.css
 %include ../../../devtools/client/themes/commandline.inc.css
 %include ../shared/plugin-doorhanger.inc.css
-%include ../shared/login-doorhanger.inc.css
 
 %include downloads/indicator.css
 
 /* On mac, the popup notification contents are indented by default and so
   the default closebutton margins from notification.css require adjustment */
 
 .click-to-play-plugins-notification-description-box > .popup-notification-closebutton {
   margin-inline-end: -6px;

deleted file mode 100644
--- a/browser/themes/shared/login-doorhanger.inc.css
+++ /dev/null
@@ -1,79 +0,0 @@
-#notification-popup[popupid="login-fill"] > .panel-arrowcontainer > .panel-arrowcontent {
-  /* Since we display a sliding subview that extends to the border, we cannot
-   * keep the default padding of arrow panels. We use the same padding in the
-   * individual content views instead. Since we removed the padding, we also
-   * have to ensure the contents are clipped to the border box. */
-  padding: 0;
-  overflow: hidden;
-}
-
-#login-fill-mainview,
-#login-fill-details {
-  padding: var(--panel-arrowcontent-padding);
-}
-
-#login-fill-doorhanger[inDetailView] > #login-fill-mainview {
-  transform: translateX(-14px);
-}
-
-#login-fill-mainview,
-#login-fill-details {
-  transition: transform 150ms;
-}
-
-#login-fill-doorhanger:not([inDetailView]) > #login-fill-details {
-  transform: translateX(105%);
-}
-
-#login-fill-doorhanger:not([inDetailView]) > #login-fill-details:-moz-locale-dir(rtl) {
-  transform: translateX(-105%);
-}
-
-#login-fill-doorhanger[inDetailView] > #login-fill-clickcapturer {
-  background-color: hsla(210,4%,10%,.1);
-}
-
-#login-fill-testing {
-  color: #b33;
-  font-weight: bold;
-}
-
-#login-fill-list {
-  border: 1px solid black;
-  max-height: 20em;
-}
-
-.login-fill-item[disabled] {
-  color: #888;
-  background-color: #fff;
-}
-
-.login-fill-item[disabled][selected] {
-  background-color: #eef;
-}
-
-.login-hostname {
-  margin: 4px;
-  font-weight: bold;
-}
-
-.login-fill-item.different-hostname > .login-hostname {
-  color: #888;
-  font-style: italic;
-}
-
-.login-username {
-  margin: 4px;
-  color: #888;
-}
-
-#login-fill-details {
-  padding: 4px;
-  background: var(--panel-arrowcontent-background);
-  color: var(--panel-arrowcontent-color);
-  background-clip: padding-box;
-  border-left: 1px solid hsla(210,4%,10%,.3);
-  box-shadow: 0 3px 5px hsla(210,4%,10%,.1),
-              0 0 7px hsla(210,4%,10%,.1);
-  margin-inline-start: 38px;
-}

--- a/browser/themes/shared/notification-icons.inc.css
+++ b/browser/themes/shared/notification-icons.inc.css
@@ -124,21 +124,16 @@
 .login-icon {
   list-style-image: url(chrome://browser/skin/notification-icons.svg#login);
 }
 
 .popup-notification-icon[popupid="password"] {
   list-style-image: url(chrome://browser/skin/notification-icons.svg#login-detailed);
 }
 
-#login-fill-notification-icon {
-  /* Temporary solution until the capture and fill doorhangers are unified. */
-  transform: scaleX(-1);
-}
-
 .camera-icon,
 .popup-notification-icon[popupid="webRTC-shareDevices"] {
   list-style-image: url(chrome://browser/skin/notification-icons.svg#camera);
 }
 
 .camera-icon.blocked-permission-icon {
   list-style-image: url(chrome://browser/skin/notification-icons.svg#camera-blocked);
 }

--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -2429,17 +2429,16 @@ notification.pluginVulnerable > .notific
 }
 
 @media (min-resolution: 1.1dppx) {
   notification.pluginVulnerable > .notification-inner > .messageCloseButton {
     list-style-image: url("chrome://global/skin/icons/close-inverted@2x.png");
   }
 }
 
-%include ../shared/login-doorhanger.inc.css
 
 %include downloads/indicator.css
 
 /* Error counter */
 
 #developer-toolbar-toolbox-button[error-count]:before {
   color: #FDF3DE;
   min-width: 16px;

--- a/build/docs/toolchains.rst
+++ b/build/docs/toolchains.rst
@@ -46,17 +46,17 @@ 2. Select ``Programming Languages`` -> `
 3. Under ``Windows and Web Development`` uncheck everything except
    ``Universal Windows App Development Tools`` and the items under it
    (should be ``Tools (1.3.1)...`` and the ``Windows 10 SDK``).
 
 Once Visual Studio 2015 Community has been installed, from a checkout
 of mozilla-central, run something like the following to produce a ZIP
 archive::
 
-   $ ./mach python build/windows_toolchain.py create-zip vs2015u2
+   $ ./mach python build/windows_toolchain.py create-zip vs2015u3
 
 The produced archive will be the argument to ``create-zip`` + ``.zip``.
 
 Firefox for Android with Gradle
 ===============================
 
 To build Firefox for Android with Gradle in automation, archives
 containing both the Gradle executable and a Maven repository

--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -269,19 +269,21 @@ def get_compiler_info(compiler, language
     ''')
 
     result = try_preprocess(compiler, language, check)
 
     if not result:
         raise FatalCheckError(
             'Unknown compiler or compiler not supported.')
 
+    # Metadata emitted by preprocessors such as GCC with LANG=ja_JP.utf-8 may
+    # have non-ASCII characters. Treat the output as bytearray.
     data = {}
     for line in result.splitlines():
-        if line.startswith('%'):
+        if line.startswith(b'%'):
             k, _, v = line.partition(' ')
             k = k.lstrip('%')
             data[k] = v.replace(' ', '').lstrip('"').rstrip('"')
             log.debug('%s = %s', k, data[k])
 
     try:
         type = CompilerType(data['COMPILER'])
     except:

--- a/build/win32/mozconfig.vs2015-win64
+++ b/build/win32/mozconfig.vs2015-win64
@@ -1,24 +1,24 @@
 if [ -z "${VSPATH}" ]; then
     TOOLTOOL_DIR=${TOOLTOOL_DIR:-$topsrcdir}
-    VSPATH="$(cd ${TOOLTOOL_DIR} && pwd)/vs2015u2"
+    VSPATH="$(cd ${TOOLTOOL_DIR} && pwd)/vs2015u3"
 fi
 
 VSWINPATH="$(cd ${VSPATH} && pwd -W)"
 
 export WINDOWSSDKDIR="${VSWINPATH}/SDK"
 export WIN32_REDIST_DIR="${VSPATH}/VC/redist/x86/Microsoft.VC140.CRT"
 export WIN_UCRT_REDIST_DIR="${VSPATH}/SDK/Redist/ucrt/DLLs/x86"
 
 export PATH="${VSPATH}/VC/bin/amd64_x86:${VSPATH}/VC/bin/amd64:${VSPATH}/VC/bin:${VSPATH}/SDK/bin/x86:${VSPATH}/SDK/bin/x64:${VSPATH}/DIA SDK/bin:${PATH}"
 export PATH="${VSPATH}/VC/redist/x86/Microsoft.VC140.CRT:${VSPATH}/VC/redist/x64/Microsoft.VC140.CRT:${VSPATH}/SDK/Redist/ucrt/DLLs/x86:${VSPATH}/SDK/Redist/ucrt/DLLs/x64:${PATH}"
 
-export INCLUDE="${VSPATH}/VC/include:${VSPATH}/VC/atlmfc/include:${VSPATH}/SDK/Include/10.0.10586.0/ucrt:${VSPATH}/SDK/Include/10.0.10586.0/shared:${VSPATH}/SDK/Include/10.0.10586.0/um:${VSPATH}/SDK/Include/10.0.10586.0/winrt:${VSPATH}/DIA SDK/include"
-export LIB="${VSPATH}/VC/lib:${VSPATH}/VC/atlmfc/lib:${VSPATH}/SDK/lib/10.0.10586.0/ucrt/x86:${VSPATH}/SDK/lib/10.0.10586.0/um/x86:${VSPATH}/DIA SDK/lib"
+export INCLUDE="${VSPATH}/VC/include:${VSPATH}/VC/atlmfc/include:${VSPATH}/SDK/Include/10.0.14393.0/ucrt:${VSPATH}/SDK/Include/10.0.14393.0/shared:${VSPATH}/SDK/Include/10.0.14393.0/um:${VSPATH}/SDK/Include/10.0.14393.0/winrt:${VSPATH}/DIA SDK/include"
+export LIB="${VSPATH}/VC/lib:${VSPATH}/VC/atlmfc/lib:${VSPATH}/SDK/lib/10.0.14393.0/ucrt/x86:${VSPATH}/SDK/lib/10.0.14393.0/um/x86:${VSPATH}/DIA SDK/lib"
 
 . $topsrcdir/build/mozconfig.vs-common
 
 mk_export_correct_style WINDOWSSDKDIR
 mk_export_correct_style INCLUDE
 mk_export_correct_style LIB
 mk_export_correct_style PATH
 mk_export_correct_style WIN32_REDIST_DIR

--- a/build/win64/mozconfig.vs2015
+++ b/build/win64/mozconfig.vs2015
@@ -1,23 +1,23 @@
 if [ -z "${VSPATH}" ]; then
     TOOLTOOL_DIR=${TOOLTOOL_DIR:-$topsrcdir}
-    VSPATH="$(cd ${TOOLTOOL_DIR} && pwd)/vs2015u2"
+    VSPATH="$(cd ${TOOLTOOL_DIR} && pwd)/vs2015u3"
 fi
 
 VSWINPATH="$(cd ${VSPATH} && pwd -W)"
 
 export WINDOWSSDKDIR="${VSWINPATH}/SDK"
 export WIN32_REDIST_DIR=${VSPATH}/VC/redist/x64/Microsoft.VC140.CRT
 export WIN_UCRT_REDIST_DIR="${VSPATH}/SDK/Redist/ucrt/DLLs/x64"
 
 export PATH="${VSPATH}/VC/bin/amd64:${VSPATH}/VC/bin:${VSPATH}/SDK/bin/x64:${VSPATH}/VC/redist/x64/Microsoft.VC140.CRT:${VSPATH}/SDK/Redist/ucrt/DLLs/x64:${VSPATH}/DIA SDK/bin/amd64:${PATH}"
 
-export INCLUDE="${VSPATH}/VC/include:${VSPATH}/VC/atlmfc/include:${VSPATH}/SDK/Include/10.0.10586.0/ucrt:${VSPATH}/SDK/Include/10.0.10586.0/shared:${VSPATH}/SDK/Include/10.0.10586.0/um:${VSPATH}/SDK/Include/10.0.10586.0/winrt:${VSPATH}/DIA SDK/include"
-export LIB="${VSPATH}/VC/lib/amd64:${VSPATH}/VC/atlmfc/lib/amd64:${VSPATH}/SDK/lib/10.0.10586.0/ucrt/x64:${VSPATH}/SDK/lib/10.0.10586.0/um/x64:${VSPATH}/DIA SDK/lib/amd64"
+export INCLUDE="${VSPATH}/VC/include:${VSPATH}/VC/atlmfc/include:${VSPATH}/SDK/Include/10.0.14393.0/ucrt:${VSPATH}/SDK/Include/10.0.14393.0/shared:${VSPATH}/SDK/Include/10.0.14393.0/um:${VSPATH}/SDK/Include/10.0.14393.0/winrt:${VSPATH}/DIA SDK/include"
+export LIB="${VSPATH}/VC/lib/amd64:${VSPATH}/VC/atlmfc/lib/amd64:${VSPATH}/SDK/lib/10.0.14393.0/ucrt/x64:${VSPATH}/SDK/lib/10.0.14393.0/um/x64:${VSPATH}/DIA SDK/lib/amd64"
 
 . $topsrcdir/build/mozconfig.vs-common
 
 mk_export_correct_style WINDOWSSDKDIR
 mk_export_correct_style INCLUDE
 mk_export_correct_style LIB
 mk_export_correct_style PATH
 mk_export_correct_style WIN32_REDIST_DIR

--- a/build/windows_toolchain.py
+++ b/build/windows_toolchain.py
@@ -79,17 +79,17 @@ VS_PATTERNS = [
     {
         'pattern': 'VC/redist/x64/Microsoft.VC140.CRT/**',
     },
     {
         'pattern': 'VC/redist/x86/Microsoft.VC140.CRT/**',
     },
 ]
 
-SDK_RELEASE = '10.0.10586.0'
+SDK_RELEASE = '10.0.14393.0'
 
 # Files from the Windows 10 SDK to install.
 SDK_PATTERNS = [
     {
         'pattern': 'bin/x64/**',
     },
     {
         'pattern': 'Include/%s/**' % SDK_RELEASE,

--- a/config/msvc-stl-wrapper.template.h
+++ b/config/msvc-stl-wrapper.template.h
@@ -54,17 +54,21 @@
 
 // C4275: When _HAS_EXCEPTIONS is set to 0, system STL header
 //        will generate the warning which we can't modify.
 // C4530: We know that code won't be able to catch exceptions,
 //        but that's OK because we're not throwing them.
 #pragma warning( push )
 #pragma warning( disable : 4275 4530 )
 
+#ifdef __clang__
+#include_next <${HEADER}>
+#else
 #include <${HEADER_PATH}>
+#endif
 
 #pragma warning( pop )
 
 #ifdef MOZ_INCLUDE_MOZALLOC_H_FROM_${HEADER}
 // See if we're in code that can use mozalloc.  NB: this duplicates
 // code in nscore.h because nscore.h pulls in prtypes.h, and chromium
 // can't build with that being included before base/basictypes.h.
 #  if !defined(XPCOM_GLUE) && !defined(NS_NO_XPCOM) && !defined(MOZ_NO_MOZALLOC)

--- a/devtools/client/aboutdebugging/test/head.js
+++ b/devtools/client/aboutdebugging/test/head.js
@@ -77,21 +77,21 @@ function addTab(url, win, backgroundTab 
 
     targetWindow.focus();
     let tab = targetBrowser.addTab(url);
     if (!backgroundTab) {
       targetBrowser.selectedTab = tab;
     }
     let linkedBrowser = tab.linkedBrowser;
 
-    linkedBrowser.addEventListener("load", function onLoad() {
-      linkedBrowser.removeEventListener("load", onLoad, true);
-      info("Tab added and finished loading: " + url);
-      done(tab);
-    }, true);
+    BrowserTestUtils.browserLoaded(linkedBrowser)
+      .then(function () {
+        info("Tab added and finished loading: " + url);
+        done(tab);
+      });
   });
 }
 
 function removeTab(tab, win) {
   info("Removing tab.");
 
   return new Promise(done => {
     let targetWindow = win || window;

--- a/devtools/client/canvasdebugger/test/head.js
+++ b/devtools/client/canvasdebugger/test/head.js
@@ -76,21 +76,21 @@ function addTab(aUrl, aWindow) {
   let deferred = promise.defer();
   let targetWindow = aWindow || window;
   let targetBrowser = targetWindow.gBrowser;
 
   targetWindow.focus();
   let tab = targetBrowser.selectedTab = targetBrowser.addTab(aUrl);
   let linkedBrowser = tab.linkedBrowser;
 
-  linkedBrowser.addEventListener("load", function onLoad() {
-    linkedBrowser.removeEventListener("load", onLoad, true);
-    info("Tab added and finished loading: " + aUrl);
-    deferred.resolve(tab);
-  }, true);
+  BrowserTestUtils.browserLoaded(linkedBrowser)
+    .then(function () {
+      info("Tab added and finished loading: " + aUrl);
+      deferred.resolve(tab);
+    });
 
   return deferred.promise;
 }
 
 function removeTab(aTab, aWindow) {
   info("Removing tab.");
 
   let deferred = promise.defer();

--- a/devtools/client/debugger/test/mochitest/head.js
+++ b/devtools/client/debugger/test/mochitest/head.js
@@ -86,21 +86,21 @@ this.addTab = function addTab(aUrl, aWin
 
   targetWindow.focus();
   let tab = targetBrowser.selectedTab = targetBrowser.addTab(aUrl);
   let linkedBrowser = tab.linkedBrowser;
 
   info("Loading frame script with url " + FRAME_SCRIPT_URL + ".");
   linkedBrowser.messageManager.loadFrameScript(FRAME_SCRIPT_URL, false);
 
-  linkedBrowser.addEventListener("load", function onLoad() {
-    linkedBrowser.removeEventListener("load", onLoad, true);
-    info("Tab added and finished loading: " + aUrl);
-    deferred.resolve(tab);
-  }, true);
+  BrowserTestUtils.browserLoaded(linkedBrowser)
+    .then(function () {
+      info("Tab added and finished loading: " + aUrl);
+      deferred.resolve(tab);
+    });
 
   return deferred.promise;
 };
 
 this.removeTab = function removeTab(aTab, aWindow) {
   info("Removing tab.");
 
   let deferred = promise.defer();

--- a/devtools/client/framework/test/browser_keybindings_01.js
+++ b/devtools/client/framework/test/browser_keybindings_01.js
@@ -1,36 +1,32 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Tests that the keybindings for opening and closing the inspector work as expected
 // Can probably make this a shared test that tests all of the tools global keybindings
-
+const TEST_URL = "data:text/html,<html><head><title>Test for the " +
+                 "highlighter keybindings</title></head><body>" +
+                 "<h1>Keybindings!</h1></body></html>"
 function test()
 {
   waitForExplicitFinish();
 
   let doc;
   let node;
   let inspector;
   let keysetMap = { };
 
-  gBrowser.selectedTab = gBrowser.addTab();
-  gBrowser.selectedBrowser.addEventListener("load", function onload() {
-    gBrowser.selectedBrowser.removeEventListener("load", onload, true);
+  addTab(TEST_URL).then(function () {
     doc = content.document;
     node = doc.querySelector("h1");
     waitForFocus(setupKeyBindingsTest);
-  }, true);
-
-  content.location = "data:text/html,<html><head><title>Test for the " +
-                     "highlighter keybindings</title></head><body>" +
-                     "<h1>Keybindings!</h1></body></html>";
+  });
 
   function buildDevtoolsKeysetMap(keyset) {
     [].forEach.call(keyset.querySelectorAll("key"), function (key) {
 
       if (!key.getAttribute("key")) {
         return;
       }
 

--- a/devtools/client/framework/test/browser_toolbox_custom_host.js
+++ b/devtools/client/framework/test/browser_toolbox_custom_host.js
@@ -1,35 +1,32 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+const TEST_URL = "data:text/html,test custom host";
+
 function test() {
   let {Toolbox} = require("devtools/client/framework/toolbox");
 
-  let toolbox, iframe, target, tab;
-
-  gBrowser.selectedTab = gBrowser.addTab();
-  target = TargetFactory.forTab(gBrowser.selectedTab);
+  let toolbox, iframe, target;
 
   window.addEventListener("message", onMessage);
 
   iframe = document.createElement("iframe");
   document.documentElement.appendChild(iframe);
 
-  gBrowser.selectedBrowser.addEventListener("load", function onLoad(evt) {
-    gBrowser.selectedBrowser.removeEventListener(evt.type, onLoad, true);
+  addTab(TEST_URL).then(function (tab) {
+    target = TargetFactory.forTab(tab);
     let options = {customIframe: iframe};
     gDevTools.showToolbox(target, null, Toolbox.HostType.CUSTOM, options)
              .then(testCustomHost, console.error)
              .then(null, console.error);
-  }, true);
-
-  content.location = "data:text/html,test custom host";
+  });
 
   function onMessage(event) {
     info("onMessage: " + event.data);
     let json = JSON.parse(event.data);
     if (json.name == "toolbox-close") {
       ok("Got the `toolbox-close` message");
       window.removeEventListener("message", onMessage);
       cleanup();
@@ -45,13 +42,13 @@ function test() {
 
   function cleanup() {
     iframe.remove();
 
     // Even if we received "toolbox-close", the toolbox may still be destroying
     // toolbox.destroy() returns a singleton promise that ensures
     // everything is cleaned up before proceeding.
     toolbox.destroy().then(() => {
-      toolbox = iframe = target = tab = null;
+      toolbox = iframe = target = null;
       finish();
     });
   }
 }

--- a/devtools/client/framework/test/browser_toolbox_dynamic_registration.js
+++ b/devtools/client/framework/test/browser_toolbox_dynamic_registration.js
@@ -1,26 +1,23 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+const TEST_URL = "data:text/html,test for dynamically registering and unregistering tools";
+
 var toolbox;
 
 function test()
 {
-  gBrowser.selectedTab = gBrowser.addTab();
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
-
-  gBrowser.selectedBrowser.addEventListener("load", function onLoad(evt) {
-    gBrowser.selectedBrowser.removeEventListener(evt.type, onLoad, true);
+  addTab(TEST_URL).then(tab => {
+    let target = TargetFactory.forTab(tab);
     gDevTools.showToolbox(target).then(testRegister);
-  }, true);
-
-  content.location = "data:text/html,test for dynamically registering and unregistering tools";
+  });
 }
 
 function testRegister(aToolbox)
 {
   toolbox = aToolbox;
   gDevTools.once("tool-registered", toolRegistered);
 
   gDevTools.registerTool({

--- a/devtools/client/framework/test/browser_toolbox_options_disable_buttons.js
+++ b/devtools/client/framework/test/browser_toolbox_options_disable_buttons.js
@@ -1,33 +1,29 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 /* import-globals-from shared-head.js */
 "use strict";
 
+const TEST_URL = "data:text/html;charset=utf8,test for dynamically " +
+                 "registering and unregistering tools";
 var doc = null, toolbox = null, panelWin = null, modifiedPrefs = [];
 
 function test() {
-  gBrowser.selectedTab = gBrowser.addTab();
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
-
-  gBrowser.selectedBrowser.addEventListener("load", function onLoad(evt) {
-    gBrowser.selectedBrowser.removeEventListener(evt.type, onLoad, true);
+  addTab(TEST_URL).then(tab => {
+    let target = TargetFactory.forTab(tab);
     gDevTools.showToolbox(target)
       .then(testSelectTool)
       .then(testToggleToolboxButtons)
       .then(testPrefsAreRespectedWhenReopeningToolbox)
       .then(cleanup, errorHandler);
-  }, true);
-
-  content.location = "data:text/html;charset=utf8,test for dynamically " +
-                     "registering and unregistering tools";
+  });
 }
 
 function testPrefsAreRespectedWhenReopeningToolbox() {
   let deferred = defer();
   let target = TargetFactory.forTab(gBrowser.selectedTab);
 
   info("Closing toolbox to test after reopening");
   gDevTools.closeToolbox(target).then(() => {

--- a/devtools/client/framework/test/browser_toolbox_options_disable_js.js
+++ b/devtools/client/framework/test/browser_toolbox_options_disable_js.js
@@ -3,25 +3,20 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Tests that disabling JavaScript for a tab works as it should.
 
 const TEST_URI = URL_ROOT + "browser_toolbox_options_disable_js.html";
 
 function test() {
-  gBrowser.selectedTab = gBrowser.addTab();
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
-
-  gBrowser.selectedBrowser.addEventListener("load", function onLoad(evt) {
-    gBrowser.selectedBrowser.removeEventListener(evt.type, onLoad, true);
+  addTab(TEST_URI).then(tab => {
+    let target = TargetFactory.forTab(tab);
     gDevTools.showToolbox(target).then(testSelectTool);
-  }, true);
-
-  BrowserTestUtils.loadURI(gBrowser.selectedBrowser, TEST_URI);
+  });
 }
 
 function testSelectTool(toolbox) {
   toolbox.once("options-selected", () => testToggleJS(toolbox));
   toolbox.selectTool("options");
 }
 
 let testToggleJS = Task.async(function* (toolbox) {

--- a/devtools/client/framework/test/browser_toolbox_options_enable_serviceworkers_testing.js
+++ b/devtools/client/framework/test/browser_toolbox_options_enable_serviceworkers_testing.js
@@ -26,29 +26,25 @@ function test() {
   SpecialPowers.pushPrefEnv({"set": [
     ["dom.serviceWorkers.exemptFromPerDomainMax", true],
     ["dom.serviceWorkers.enabled", true],
     ["dom.serviceWorkers.testing.enabled", false]
   ]}, init);
 }
 
 function init() {
-  let tab = gBrowser.selectedTab = gBrowser.addTab();
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
-  let linkedBrowser = tab.linkedBrowser;
-
-  linkedBrowser.messageManager.loadFrameScript(COMMON_FRAME_SCRIPT_URL, false);
-  linkedBrowser.messageManager.loadFrameScript(FRAME_SCRIPT_URL, false);
+  addTab(TEST_URI).then(tab => {
+    let target = TargetFactory.forTab(tab);
+    let linkedBrowser = tab.linkedBrowser;
 
-  gBrowser.selectedBrowser.addEventListener("load", function onLoad(evt) {
-    gBrowser.selectedBrowser.removeEventListener(evt.type, onLoad, true);
+    linkedBrowser.messageManager.loadFrameScript(COMMON_FRAME_SCRIPT_URL, false);
+    linkedBrowser.messageManager.loadFrameScript(FRAME_SCRIPT_URL, false);
+
     gDevTools.showToolbox(target).then(testSelectTool);
-  }, true);
-
-  content.location = TEST_URI;
+  });
 }
 
 function testSelectTool(aToolbox) {
   toolbox = aToolbox;
   toolbox.once("options-selected", start);
   toolbox.selectTool("options");
 }
 

--- a/devtools/client/framework/test/browser_toolbox_raise.js
+++ b/devtools/client/framework/test/browser_toolbox_raise.js
@@ -1,30 +1,27 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+const TEST_URL = "data:text/html,test for opening toolbox in different hosts";
+
 var {Toolbox} = require("devtools/client/framework/toolbox");
 
-var toolbox, target, tab1, tab2;
+var toolbox, tab1, tab2;
 
 function test() {
-  gBrowser.selectedTab = tab1 = gBrowser.addTab();
-  tab2 = gBrowser.addTab();
-  target = TargetFactory.forTab(gBrowser.selectedTab);
-
-  gBrowser.selectedBrowser.addEventListener("load", function onLoad(evt) {
-    gBrowser.selectedBrowser.removeEventListener(evt.type, onLoad, true);
+  addTab(TEST_URL).then(tab => {
+    tab2 = gBrowser.addTab();
+    let target = TargetFactory.forTab(tab);
     gDevTools.showToolbox(target)
              .then(testBottomHost, console.error)
              .then(null, console.error);
-  }, true);
-
-  content.location = "data:text/html,test for opening toolbox in different hosts";
+  });
 }
 
 function testBottomHost(aToolbox) {
   toolbox = aToolbox;
 
   // switch to another tab and test toolbox.raise()
   gBrowser.selectedTab = tab2;
   executeSoon(function () {
@@ -68,14 +65,14 @@ function onFocus() {
   // Now raise toolbox.
   toolbox.raise();
 }
 
 function cleanup() {
   Services.prefs.setCharPref("devtools.toolbox.host", Toolbox.HostType.BOTTOM);
 
   toolbox.destroy().then(function () {
-    toolbox = target = null;
+    toolbox = null;
     gBrowser.removeCurrentTab();
     gBrowser.removeCurrentTab();
     finish();
   });
 }

--- a/devtools/client/framework/test/browser_toolbox_ready.js
+++ b/devtools/client/framework/test/browser_toolbox_ready.js
@@ -1,27 +1,21 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
-function test() {
-  gBrowser.selectedTab = gBrowser.addTab();
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
+const TEST_URL = "data:text/html,test for toolbox being ready";
 
-  const onLoad = Task.async(function* (evt) {
-    gBrowser.selectedBrowser.removeEventListener("load", onLoad);
-
-    const toolbox = yield gDevTools.showToolbox(target, "webconsole");
-    ok(toolbox.isReady, "toolbox isReady is set");
-    ok(toolbox.threadClient, "toolbox has a thread client");
+add_task(function* () {
+  let tab = yield addTab(TEST_URL);
+  let target = TargetFactory.forTab(tab);
 
-    const toolbox2 = yield gDevTools.showToolbox(toolbox.target, toolbox.toolId);
-    is(toolbox2, toolbox, "same toolbox");
+  const toolbox = yield gDevTools.showToolbox(target, "webconsole");
+  ok(toolbox.isReady, "toolbox isReady is set");
+  ok(toolbox.threadClient, "toolbox has a thread client");
 
-    yield toolbox.destroy();
-    gBrowser.removeCurrentTab();
-    finish();
-  });
+  const toolbox2 = yield gDevTools.showToolbox(toolbox.target, toolbox.toolId);
+  is(toolbox2, toolbox, "same toolbox");
 
-  gBrowser.selectedBrowser.addEventListener("load", onLoad, true);
-  content.location = "data:text/html,test for toolbox being ready";
-}
+  yield toolbox.destroy();
+  gBrowser.removeCurrentTab();
+});

--- a/devtools/client/framework/test/browser_two_tabs.js
+++ b/devtools/client/framework/test/browser_two_tabs.js
@@ -25,27 +25,24 @@ function test() {
     DebuggerServer.addBrowserActors();
   }
 
   openTabs();
 }
 
 function openTabs() {
   // Open two tabs, select the second
-  gTab1 = gBrowser.addTab(TAB_URL_1);
-  gTab1.linkedBrowser.addEventListener("load", function onLoad1(evt) {
-    gTab1.linkedBrowser.removeEventListener("load", onLoad1);
-
-    gTab2 = gBrowser.selectedTab = gBrowser.addTab(TAB_URL_2);
-    gTab2.linkedBrowser.addEventListener("load", function onLoad2(evt) {
-      gTab2.linkedBrowser.removeEventListener("load", onLoad2);
+  addTab(TAB_URL_1).then(tab1 => {
+    gTab1 = tab1;
+    addTab(TAB_URL_2).then(tab2 => {
+      gTab2 = tab2;
 
       connect();
-    }, true);
-  }, true);
+    });
+  });
 }
 
 function connect() {
   // Connect to debugger server to fetch the two tab actors
   gClient = new DebuggerClient(DebuggerServer.connectPipe());
   gClient.connect()
     .then(() => gClient.listTabs())
     .then(response => {

--- a/devtools/client/framework/test/helper_disable_cache.js
+++ b/devtools/client/framework/test/helper_disable_cache.js
@@ -86,22 +86,20 @@ function* setDisableCacheCheckboxChecked
     yield waitForTick();
   }
 }
 
 function reloadTab(tabX) {
   let def = defer();
   let browser = gBrowser.selectedBrowser;
 
-  // once() doesn't work here so we use a standard handler instead.
-  browser.addEventListener("load", function onLoad() {
-    browser.removeEventListener("load", onLoad, true);
+  BrowserTestUtils.browserLoaded(browser).then(function () {
     info("Reloaded tab " + tabX.title);
     def.resolve();
-  }, true);
+  });
 
   info("Reloading tab " + tabX.title);
   let mm = getFrameScript();
   mm.sendAsyncMessage("devtools:test:reload");
 
   return def.promise;
 }
 

--- a/devtools/client/framework/test/shared-head.js
+++ b/devtools/client/framework/test/shared-head.js
@@ -108,17 +108,17 @@ registerCleanupFunction(function* cleanu
  * Add a new test tab in the browser and load the given url.
  * @param {String} url The url to be loaded in the new tab
  * @return a promise that resolves to the tab object when the url is loaded
  */
 var addTab = Task.async(function* (url) {
   info("Adding a new tab with URL: " + url);
 
   let tab = gBrowser.selectedTab = gBrowser.addTab(url);
-  yield once(gBrowser.selectedBrowser, "load", true);
+  yield BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
 
   info("Tab added and finished loading");
 
   return tab;
 });
 
 /**
  * Remove the given tab.
@@ -137,17 +137,17 @@ var removeTab = Task.async(function* (ta
 
 /**
  * Refresh the given tab.
  * @param {Object} tab The tab to be refreshed.
  * @return Promise<undefined> resolved when the tab is successfully refreshed.
  */
 var refreshTab = Task.async(function*(tab) {
   info("Refreshing tab.");
-  const finished = once(gBrowser.selectedBrowser, "load", true);
+  const finished = BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
   gBrowser.reloadTab(gBrowser.selectedTab);
   yield finished;
   info("Tab finished refreshing.");
 });
 
 /**
  * Simulate a key event from a <key> element.
  * @param {DOMNode} key
@@ -286,19 +286,17 @@ function waitForTick() {
  * This shouldn't be used in the tests, but is useful when writing new tests or
  * debugging existing tests in order to introduce delays in the test steps
  *
  * @param {Number} ms
  *        The time to wait
  * @return A promise that resolves when the time is passed
  */
 function wait(ms) {
-  let def = defer();
-  content.setTimeout(def.resolve, ms);
-  return def.promise;
+  return new promise(resolve => setTimeout(resolve, ms));
 }
 
 /**
  * Open the toolbox in a given tab.
  * @param {XULNode} tab The tab the toolbox should be opened in.
  * @param {String} toolId Optional. The ID of the tool to be selected.
  * @param {String} hostType Optional. The type of toolbox host to be used.
  * @return {Promise} Resolves with the toolbox, when it has been opened.

--- a/devtools/client/inspector/computed/test/browser_computed_search-filter_context-menu.js
+++ b/devtools/client/inspector/computed/test/browser_computed_search-filter_context-menu.js
@@ -47,17 +47,17 @@ add_task(function* () {
   yield onContextMenuHidden;
 
   info("Copy text in search field using the context menu");
   searchField.value = TEST_INPUT;
   searchField.select();
   EventUtils.synthesizeMouse(searchField, 2, 2,
     {type: "contextmenu", button: 2}, win);
   yield onContextMenuPopup;
-  yield waitForClipboard(() => cmdCopy.click(), TEST_INPUT);
+  yield waitForClipboardPromise(() => cmdCopy.click(), TEST_INPUT);
   searchContextMenu.hidePopup();
   yield onContextMenuHidden;
 
   info("Reopen context menu and check command properties");
   EventUtils.synthesizeMouse(searchField, 2, 2,
     {type: "contextmenu", button: 2}, win);
   yield onContextMenuPopup;
 

--- a/devtools/client/inspector/computed/test/browser_computed_select-and-copy-styles.js
+++ b/devtools/client/inspector/computed/test/browser_computed_select-and-copy-styles.js
@@ -57,17 +57,17 @@ function* checkCopySelection(view) {
   info("Checking that cssHtmlTree.siBoundCopy() returns the correct " +
     "clipboard value");
 
   let expectedPattern = "font-family: helvetica,sans-serif;[\\r\\n]+" +
                         "font-size: 16px;[\\r\\n]+" +
                         "font-variant-caps: small-caps;[\\r\\n]*";
 
   try {
-    yield waitForClipboard(() => fireCopyEvent(props[0]),
+    yield waitForClipboardPromise(() => fireCopyEvent(props[0]),
                            () => checkClipboardData(expectedPattern));
   } catch (e) {
     failedClipboard(expectedPattern);
   }
 }
 
 function* checkSelectAll(view) {
   info("Testing select-all copy");
@@ -79,17 +79,17 @@ function* checkSelectAll(view) {
     "clipboard value");
   view._contextmenu._onSelectAll();
   let expectedPattern = "color: rgb\\(255, 255, 0\\);[\\r\\n]+" +
                         "font-family: helvetica,sans-serif;[\\r\\n]+" +
                         "font-size: 16px;[\\r\\n]+" +
                         "font-variant-caps: small-caps;[\\r\\n]*";
 
   try {
-    yield waitForClipboard(() => fireCopyEvent(prop),
+    yield waitForClipboardPromise(() => fireCopyEvent(prop),
                            () => checkClipboardData(expectedPattern));
   } catch (e) {
     failedClipboard(expectedPattern);
   }
 }
 
 function checkClipboardData(expectedPattern) {
   let actual = SpecialPowers.getClipboardData("text/unicode");

--- a/devtools/client/inspector/markup/test/browser_markup_links_05.js
+++ b/devtools/client/inspector/markup/test/browser_markup_links_05.js
@@ -20,17 +20,17 @@ add_task(function* () {
   openContextMenuAndGetAllItems(inspector, {
     target: editor.attrElements.get("poster").querySelector(".link"),
   });
 
   info("Follow the link and wait for the new tab to open");
   let onTabOpened = once(gBrowser.tabContainer, "TabOpen");
   inspector.onFollowLink();
   let {target: tab} = yield onTabOpened;
-  yield waitForTabLoad(tab);
+  yield BrowserTestUtils.browserLoaded(tab.linkedBrowser);
 
   ok(true, "A new tab opened");
   is(tab.linkedBrowser.currentURI.spec, URL_ROOT + "doc_markup_tooltip.png",
     "The URL for the new tab is correct");
   gBrowser.removeTab(tab);
 
   info("Select a node with a IDREF attribute");
   yield selectNode("label", inspector);
@@ -62,21 +62,8 @@ add_task(function* () {
   let onFailed = inspector.once("idref-attribute-link-failed");
   inspector.onFollowLink();
   yield onFailed;
 
   ok(true, "The node selection failed");
   is(inspector.selection.nodeFront.tagName.toLowerCase(), "output",
     "The <output> node is still selected");
 });
-
-function waitForTabLoad(tab) {
-  let def = defer();
-  tab.addEventListener("load", function onLoad(e) {
-    // Skip load event for about:blank
-    if (tab.linkedBrowser.currentURI.spec === "about:blank") {
-      return;
-    }
-    tab.removeEventListener("load", onLoad);
-    def.resolve();
-  });
-  return def.promise;
-}

--- a/devtools/client/inspector/markup/test/browser_markup_links_07.js
+++ b/devtools/client/inspector/markup/test/browser_markup_links_07.js
@@ -53,29 +53,16 @@ add_task(function* () {
 
   info("Try to follow link wiith middle-click, check no new node selected");
   yield followLinkNoNewNode(linkEl, false, inspector);
 
   info("Try to follow link wiith meta/ctrl-click, check no new node selected");
   yield followLinkNoNewNode(linkEl, true, inspector);
 });
 
-function waitForTabLoad(tab) {
-  let def = defer();
-  tab.addEventListener("load", function onLoad() {
-    // Skip load event for about:blank
-    if (tab.linkedBrowser.currentURI.spec === "about:blank") {
-      return;
-    }
-    tab.removeEventListener("load", onLoad);
-    def.resolve();
-  });
-  return def.promise;
-}
-
 function performMouseDown(linkEl, metactrl) {
   let evt = linkEl.ownerDocument.createEvent("MouseEvents");
 
   let button = -1;
 
   if (metactrl) {
     info("Performing Meta/Ctrl+Left Click");
     button = 0;
@@ -90,17 +77,17 @@ function performMouseDown(linkEl, metact
 
   linkEl.dispatchEvent(evt);
 }
 
 function* followLinkWaitForTab(linkEl, isMetaClick, expectedTabURI) {
   let onTabOpened = once(gBrowser.tabContainer, "TabOpen");
   performMouseDown(linkEl, isMetaClick);
   let {target} = yield onTabOpened;
-  yield waitForTabLoad(target);
+  yield BrowserTestUtils.browserLoaded(target.linkedBrowser);
   ok(true, "A new tab opened");
   is(target.linkedBrowser.currentURI.spec, expectedTabURI,
      "The URL for the new tab is correct");
   gBrowser.removeTab(target);
 }
 
 function* followLinkWaitForNewNode(linkEl, isMetaClick, inspector) {
   let onSelection = inspector.selection.once("new-node-front");

--- a/devtools/client/inspector/markup/test/head.js
+++ b/devtools/client/inspector/markup/test/head.js
@@ -267,28 +267,16 @@ function searchUsingSelectorSearch(selec
   info("Entering \"" + selector + "\" into the selector-search input field");
   let field = getSelectorSearchBox(inspector);
   field.focus();
   field.value = selector;
   EventUtils.sendKey("return", inspector.panelWin);
 }
 
 /**
- * This shouldn't be used in the tests, but is useful when writing new tests or
- * debugging existing tests in order to introduce delays in the test steps
- * @param {Number} ms The time to wait
- * @return A promise that resolves when the time is passed
- */
-function wait(ms) {
-  let def = defer();
-  setTimeout(def.resolve, ms);
-  return def.promise;
-}
-
-/**
  * Check to see if the inspector menu items for editing are disabled.
  * Things like Edit As HTML, Delete Node, etc.
  * @param {NodeFront} nodeFront
  * @param {InspectorPanel} inspector
  * @param {Boolean} assert Should this function run assertions inline.
  * @return A promise that resolves with a boolean indicating whether
  *         the menu items are disabled once the menu has been checked.
  */

--- a/devtools/client/inspector/rules/test/browser_rules_copy_styles.js
+++ b/devtools/client/inspector/rules/test/browser_rules_copy_styles.js
@@ -262,17 +262,17 @@ function* checkCopyStyle(view, node, men
      visible.copySelector);
 
   is(menuitemCopyRule.visible,
      visible.copyRule,
      "Copy Rule visible attribute is as expected: " +
      visible.copyRule);
 
   try {
-    yield waitForClipboard(() => menuItem.click(),
+    yield waitForClipboardPromise(() => menuItem.click(),
       () => checkClipboardData(expectedPattern));
   } catch (e) {
     failedClipboard(expectedPattern);
   }
 }
 
 function* disableProperty(view, index) {
   let ruleEditor = getRuleViewRuleEditor(view, 1);

--- a/devtools/client/inspector/rules/test/browser_rules_search-filter_context-menu.js
+++ b/devtools/client/inspector/rules/test/browser_rules_search-filter_context-menu.js
@@ -46,17 +46,17 @@ add_task(function* () {
   yield onContextMenuHidden;
 
   info("Copy text in search field using the context menu");
   searchField.value = TEST_INPUT;
   searchField.select();
   EventUtils.synthesizeMouse(searchField, 2, 2,
     {type: "contextmenu", button: 2}, win);
   yield onContextMenuPopup;
-  yield waitForClipboard(() => cmdCopy.click(), TEST_INPUT);
+  yield waitForClipboardPromise(() => cmdCopy.click(), TEST_INPUT);
   searchContextMenu.hidePopup();
   yield onContextMenuHidden;
 
   info("Reopen context menu and check command properties");
   EventUtils.synthesizeMouse(searchField, 2, 2,
     {type: "contextmenu", button: 2}, win);
   yield onContextMenuPopup;
 

--- a/devtools/client/inspector/rules/test/browser_rules_select-and-copy-styles.js
+++ b/devtools/client/inspector/rules/test/browser_rules_select-and-copy-styles.js
@@ -70,17 +70,17 @@ function* checkCopySelection(view) {
   let allMenuItems = openStyleContextMenuAndGetAllItems(view, prop);
   let menuitemCopy = allMenuItems.find(item => item.label ===
     STYLE_INSPECTOR_L10N.getStr("styleinspector.contextmenu.copy"));
 
   ok(menuitemCopy.visible,
     "Copy menu item is displayed as expected");
 
   try {
-    yield waitForClipboard(() => menuitemCopy.click(),
+    yield waitForClipboardPromise(() => menuitemCopy.click(),
       () => checkClipboardData(expectedPattern));
   } catch (e) {
     failedClipboard(expectedPattern);
   }
 }
 
 function* checkSelectAll(view) {
   info("Testing select-all copy");
@@ -104,17 +104,17 @@ function* checkSelectAll(view) {
   let allMenuItems = openStyleContextMenuAndGetAllItems(view, prop);
   let menuitemCopy = allMenuItems.find(item => item.label ===
     STYLE_INSPECTOR_L10N.getStr("styleinspector.contextmenu.copy"));
 
   ok(menuitemCopy.visible,
     "Copy menu item is displayed as expected");
 
   try {
-    yield waitForClipboard(() => menuitemCopy.click(),
+    yield waitForClipboardPromise(() => menuitemCopy.click(),
       () => checkClipboardData(expectedPattern));
   } catch (e) {
     failedClipboard(expectedPattern);
   }
 }
 
 function* checkCopyEditorValue(view) {
   info("Testing CSS property editor value copy");
@@ -132,17 +132,17 @@ function* checkCopyEditorValue(view) {
   let allMenuItems = openStyleContextMenuAndGetAllItems(view, editor.input);
   let menuitemCopy = allMenuItems.find(item => item.label ===
     STYLE_INSPECTOR_L10N.getStr("styleinspector.contextmenu.copy"));
 
   ok(menuitemCopy.visible,
     "Copy menu item is displayed as expected");
 
   try {
-    yield waitForClipboard(() => menuitemCopy.click(),
+    yield waitForClipboardPromise(() => menuitemCopy.click(),
       () => checkClipboardData(expectedPattern));
   } catch (e) {
     failedClipboard(expectedPattern);
   }
 }
 
 function checkClipboardData(expectedPattern) {
   let actual = SpecialPowers.getClipboardData("text/unicode");

--- a/devtools/client/inspector/shared/test/browser_styleinspector_context-menu-copy-color_02.js
+++ b/devtools/client/inspector/shared/test/browser_styleinspector_context-menu-copy-color_02.js
@@ -34,17 +34,17 @@ function* testCopyToClipboard(inspector,
     .querySelector(".ruleview-colorswatch");
 
   let allMenuItems = openStyleContextMenuAndGetAllItems(view, element);
   let menuitemCopyColor = allMenuItems.find(item => item.label ===
     STYLE_INSPECTOR_L10N.getStr("styleinspector.contextmenu.copyColor"));
 
   ok(menuitemCopyColor.visible, "Copy color is visible");
 
-  yield waitForClipboard(() => menuitemCopyColor.click(),
+  yield waitForClipboardPromise(() => menuitemCopyColor.click(),
     "#123ABC");
 
   EventUtils.synthesizeKey("VK_ESCAPE", { });
 }
 
 function* testManualEdit(inspector, view) {
   info("Testing manually edited colors");
   yield selectNode("div", inspector);

--- a/devtools/client/inspector/shared/test/browser_styleinspector_context-menu-copy-urls.js
+++ b/devtools/client/inspector/shared/test/browser_styleinspector_context-menu-copy-urls.js
@@ -82,22 +82,22 @@ function* testCopyUrlToClipboard({view, 
   info("Context menu is displayed");
   ok(menuitemCopyUrl.visible,
      "\"Copy URL\" menu entry is displayed");
   ok(menuitemCopyImageDataUrl.visible,
      "\"Copy Image Data-URL\" menu entry is displayed");
 
   if (type == "data-uri") {
     info("Click Copy Data URI and wait for clipboard");
-    yield waitForClipboard(() => {
+    yield waitForClipboardPromise(() => {
       return menuitemCopyImageDataUrl.click();
     }, expected);
   } else {
     info("Click Copy URL and wait for clipboard");
-    yield waitForClipboard(() => {
+    yield waitForClipboardPromise(() => {
       return menuitemCopyUrl.click();
     }, expected);
   }
 
   info("Hide context menu");
 }
 
 function getBackgroundImageProperty(view, selector) {

--- a/devtools/client/inspector/test/browser_inspector_highlighter-eyedropper-clipboard.js
+++ b/devtools/client/inspector/test/browser_inspector_highlighter-eyedropper-clipboard.js
@@ -18,17 +18,17 @@ add_task(function* () {
        waitForElementAttributeSet, waitForElementAttributeRemoved} = helper;
 
   info("Show the eyedropper with the copyOnSelect option");
   yield show("html", {copyOnSelect: true});
 
   info("Make sure to wait until the eyedropper is done taking a screenshot of the page");
   yield waitForElementAttributeSet("root", "drawn", helper);
 
-  yield waitForClipboard(() => {
+  yield waitForClipboardPromise(() => {
     info("Activate the eyedropper so the background color is copied");
     EventUtils.synthesizeKey("VK_RETURN", {});
   }, "#FF0000");
 
   ok(true, "The clipboard contains the right value");
 
   yield waitForElementAttributeRemoved("root", "drawn", helper);
   yield waitForElementAttributeSet("root", "hidden", helper);

--- a/devtools/client/inspector/test/browser_inspector_keyboard-shortcuts-copy-outerhtml.js
+++ b/devtools/client/inspector/test/browser_inspector_keyboard-shortcuts-copy-outerhtml.js
@@ -29,17 +29,17 @@ add_task(function* () {
 function* setSelectionNodeFront(node, inspector) {
   let updated = inspector.once("inspector-updated");
   inspector.selection.setNodeFront(node);
   yield updated;
 }
 
 function* checkClipboard(expectedText, node) {
   try {
-    yield waitForClipboard(() => fireCopyEvent(node), expectedText);
+    yield waitForClipboardPromise(() => fireCopyEvent(node), expectedText);
     ok(true, "Clipboard successfully filled with : " + expectedText);
   } catch (e) {
     ok(false, "Clipboard could not be filled with the expected text : " +
               expectedText);
   }
 }
 
 function getElementByType(inspector, type) {

--- a/devtools/client/inspector/test/browser_inspector_menu-02-copy-items.js
+++ b/devtools/client/inspector/test/browser_inspector_menu-02-copy-items.js
@@ -39,11 +39,11 @@ add_task(function* () {
   for (let {desc, id, selector, text} of COPY_ITEMS_TEST_DATA) {
     info("Testing " + desc);
     yield selectNode(selector, inspector);
 
     let allMenuItems = openContextMenuAndGetAllItems(inspector);
     let item = allMenuItems.find(i => i.id === id);
     ok(item, "The popup has a " + desc + " menu item.");
 
-    yield waitForClipboard(() => item.click(), text);
+    yield waitForClipboardPromise(() => item.click(), text);
   }
 });

--- a/devtools/client/inspector/test/browser_inspector_search-filter_context-menu.js
+++ b/devtools/client/inspector/test/browser_inspector_search-filter_context-menu.js
@@ -45,17 +45,17 @@ add_task(function* () {
   yield onContextMenuHidden;
 
   info("Copy text in search field using the context menu");
   searchBox.value = TEST_INPUT;
   searchBox.select();
   EventUtils.synthesizeMouse(searchBox, 2, 2,
     {type: "contextmenu", button: 2}, win);
   yield onContextMenuPopup;
-  yield waitForClipboard(() => cmdCopy.click(), TEST_INPUT);
+  yield waitForClipboardPromise(() => cmdCopy.click(), TEST_INPUT);
   searchContextMenu.hidePopup();
   yield onContextMenuHidden;
 
   info("Reopen context menu and check command properties");
   EventUtils.synthesizeMouse(searchBox, 2, 2,
     {type: "contextmenu", button: 2}, win);
   yield onContextMenuPopup;
 

--- a/devtools/client/inspector/test/head.js
+++ b/devtools/client/inspector/test/head.js
@@ -614,33 +614,16 @@ function waitForStyleEditor(toolbox, hre
       panel.UI.on("editor-selected", gotEditor);
     }
   });
 
   return def.promise;
 }
 
 /**
- * @see SimpleTest.waitForClipboard
- *
- * @param {Function} setup
- *        Function to execute before checking for the
- *        clipboard content
- * @param {String|Function} expected
- *        An expected string or validator function
- * @return a promise that resolves when the expected string has been found or
- * the validator function has returned true, rejects otherwise.
- */
-function waitForClipboard(setup, expected) {
-  let def = defer();
-  SimpleTest.waitForClipboard(expected, setup, def.resolve, def.reject);
-  return def.promise;
-}
-
-/**
  * Checks if document's active element is within the given element.
  * @param  {HTMLDocument}  doc document with active element in question
  * @param  {DOMNode}       container element tested on focus containment
  * @return {Boolean}
  */
 function containsFocus(doc, container) {
   let elm = doc.activeElement;
   while (elm) {
@@ -657,18 +640,17 @@ function containsFocus(doc, container) {
  * does and completes the load event.
  *
  * @return a promise that resolves to the tab object
  */
 var waitForTab = Task.async(function* () {
   info("Waiting for a tab to open");
   yield once(gBrowser.tabContainer, "TabOpen");
   let tab = gBrowser.selectedTab;
-  let browser = tab.linkedBrowser;
-  yield once(browser, "load", true);
+  yield BrowserTestUtils.browserLoaded(tab.linkedBrowser);
   info("The tab load completed");
   return tab;
 });
 
 /**
  * Simulate the key input for the given input in the window.
  *
  * @param {String} input

--- a/devtools/client/projecteditor/test/head.js
+++ b/devtools/client/projecteditor/test/head.js
@@ -52,25 +52,23 @@ registerCleanupFunction(() => {
  * Add a new test tab in the browser and load the given url.
  * @param {String} url The url to be loaded in the new tab
  * @return a promise that resolves to the tab object when the url is loaded
  */
 function addTab(url) {
   info("Adding a new tab with URL: '" + url + "'");
   let def = promise.defer();
 
-  let tab = gBrowser.selectedTab = gBrowser.addTab();
-  gBrowser.selectedBrowser.addEventListener("load", function onload() {
-    gBrowser.selectedBrowser.removeEventListener("load", onload, true);
+  let tab = gBrowser.selectedTab = gBrowser.addTab(url);
+  BrowserTestUtils.browserLoaded(tab.linkedBrowser).then(function () {
     info("URL '" + url + "' loading complete");
     waitForFocus(() => {
       def.resolve(tab);
     }, content);
-  }, true);
-  content.location = url;
+  });
 
   return def.promise;
 }
 
 /**
  * Some tests may need to import one or more of the test helper scripts.
  * A test helper script is simply a js file that contains common test code that
  * is either not common-enough to be in head.js, or that is located in a separate

--- a/devtools/client/responsivedesign/test/head.js
+++ b/devtools/client/responsivedesign/test/head.js
@@ -190,28 +190,22 @@ function openRuleView() {
 var addTab = Task.async(function* (url) {
   info("Adding a new tab with URL: '" + url + "'");
 
   window.focus();
 
   let tab = gBrowser.selectedTab = gBrowser.addTab(url);
   let browser = tab.linkedBrowser;
 
-  yield once(browser, "load", true);
+  yield BrowserTestUtils.browserLoaded(browser);
   info("URL '" + url + "' loading complete");
 
   return tab;
 });
 
-function wait(ms) {
-  let def = promise.defer();
-  setTimeout(def.resolve, ms);
-  return def.promise;
-}
-
 /**
  * Waits for the next load to complete in the current browser.
  *
  * @return promise
  */
 function waitForDocLoadComplete(aBrowser = gBrowser) {
   let deferred = promise.defer();
   let progressListener = {

--- a/devtools/client/shadereditor/test/head.js
+++ b/devtools/client/shadereditor/test/head.js
@@ -71,21 +71,20 @@ function addTab(aUrl, aWindow) {
   let deferred = promise.defer();
   let targetWindow = aWindow || window;
   let targetBrowser = targetWindow.gBrowser;
 
   targetWindow.focus();
   let tab = targetBrowser.selectedTab = targetBrowser.addTab(aUrl);
   let linkedBrowser = tab.linkedBrowser;
 
-  linkedBrowser.addEventListener("load", function onLoad() {
-    linkedBrowser.removeEventListener("load", onLoad, true);
+  BrowserTestUtils.browserLoaded(linkedBrowser).then(function () {
     info("Tab added and finished loading: " + aUrl);
     deferred.resolve(tab);
-  }, true);
+  });
 
   return deferred.promise;
 }
 
 function removeTab(aTab, aWindow) {
   info("Removing tab.");
 
   let deferred = promise.defer();

--- a/devtools/client/sourceeditor/test/browser_codemirror.js
+++ b/devtools/client/sourceeditor/test/browser_codemirror.js
@@ -7,19 +7,12 @@
 const URI = "chrome://mochitests/content/browser/devtools/client/" +
             "sourceeditor/test/codemirror/codemirror.html";
 loadHelperScript("helper_codemirror_runner.js");
 
 function test() {
   requestLongerTimeout(3);
   waitForExplicitFinish();
 
-  let tab = gBrowser.addTab();
-  gBrowser.selectedTab = tab;
-
-  let browser = gBrowser.getBrowserForTab(tab);
-  browser.addEventListener("load", function onLoad() {
-    browser.removeEventListener("load", onLoad, true);
-    runCodeMirrorTest(browser);
-  }, true);
-
-  browser.loadURI(URI);
+  addTab(URI).then(function (tab) {
+    runCodeMirrorTest(tab.linkedBrowser);
+  });
 }

--- a/devtools/client/sourceeditor/test/browser_css_autocompletion.js
+++ b/devtools/client/sourceeditor/test/browser_css_autocompletion.js
@@ -74,23 +74,20 @@ let doc = null;
 let index = 0;
 let completer = null;
 let progress;
 let progressDiv;
 let inspector;
 
 function test() {
   waitForExplicitFinish();
-  gBrowser.selectedTab = gBrowser.addTab();
-  gBrowser.selectedBrowser.addEventListener("load", function onload() {
-    gBrowser.selectedBrowser.removeEventListener("load", onload, true);
+  addTab(TEST_URI).then(function () {
     doc = content.document;
     runTests();
-  }, true);
-  content.location = TEST_URI;
+  });
 }
 
 function runTests() {
   progress = doc.getElementById("progress");
   progressDiv = doc.querySelector("#progress > div");
   let target = TargetFactory.forTab(gBrowser.selectedTab);
   target.makeRemote().then(() => {
     inspector = InspectorFront(target.client, target.form);

--- a/devtools/client/sourceeditor/test/browser_vimemacs.js
+++ b/devtools/client/sourceeditor/test/browser_vimemacs.js
@@ -6,19 +6,12 @@
 const URI = "chrome://mochitests/content/browser/devtools/client" +
             "/sourceeditor/test/codemirror/vimemacs.html";
 loadHelperScript("helper_codemirror_runner.js");
 
 function test() {
   requestLongerTimeout(4);
   waitForExplicitFinish();
 
-  let tab = gBrowser.addTab();
-  gBrowser.selectedTab = tab;
-
-  let browser = gBrowser.getBrowserForTab(tab);
-  browser.addEventListener("load", function onLoad() {
-    browser.removeEventListener("load", onLoad, true);
-    runCodeMirrorTest(browser);
-  }, true);
-
-  browser.loadURI(URI);
+  addTab(URI).then(function (tab) {
+    runCodeMirrorTest(tab.linkedBrowser);
+  });
 }

--- a/devtools/client/sourceeditor/test/head.js
+++ b/devtools/client/sourceeditor/test/head.js
@@ -17,28 +17,26 @@ SimpleTest.registerCleanupFunction(() =>
 });
 
 /**
  * Open a new tab at a URL and call a callback on load
  */
 function addTab(url, callback) {
   waitForExplicitFinish();
 
-  gBrowser.selectedTab = gBrowser.addTab();
-  content.location = url;
-
+  gBrowser.selectedTab = gBrowser.addTab(url);
   let tab = gBrowser.selectedTab;
   let browser = gBrowser.getBrowserForTab(tab);
 
-  function onTabLoad() {
-    browser.removeEventListener("load", onTabLoad, true);
-    callback(browser, tab, browser.contentDocument);
-  }
-
-  browser.addEventListener("load", onTabLoad, true);
+  return BrowserTestUtils.browserLoaded(browser).then(function () {
+    if (typeof(callback) == "function") {
+      callback(browser, tab, browser.contentDocument);
+    }
+    return tab;
+  });
 }
 
 function promiseTab(url) {
   return new Promise(resolve =>
     addTab(url, resolve));
 }
 
 function promiseWaitForFocus() {

--- a/devtools/client/styleeditor/test/head.js
+++ b/devtools/client/styleeditor/test/head.js
@@ -24,21 +24,21 @@ const TEST_HOST = "mochi.test:8888";
 var addTab = function (url, win) {
   info("Adding a new tab with URL: '" + url + "'");
   let def = defer();
 
   let targetWindow = win || window;
   let targetBrowser = targetWindow.gBrowser;
 
   let tab = targetBrowser.selectedTab = targetBrowser.addTab(url);
-  targetBrowser.selectedBrowser.addEventListener("load", function onload() {
-    targetBrowser.selectedBrowser.removeEventListener("load", onload, true);
-    info("URL '" + url + "' loading complete");
-    def.resolve(tab);
-  }, true);
+  BrowserTestUtils.browserLoaded(targetBrowser.selectedBrowser)
+    .then(function () {
+      info("URL '" + url + "' loading complete");
+      def.resolve(tab);
+    });
 
   return def.promise;
 };
 
 /**
  * Navigate the currently selected tab to a new URL and wait for it to load.
  * @param {String} url The url to be loaded in the current tab.
  * @return a promise that resolves when the page has fully loaded.

--- a/devtools/client/webaudioeditor/test/head.js
+++ b/devtools/client/webaudioeditor/test/head.js
@@ -68,21 +68,20 @@ function addTab(aUrl, aWindow) {
   let deferred = Promise.defer();
   let targetWindow = aWindow || window;
   let targetBrowser = targetWindow.gBrowser;
 
   targetWindow.focus();
   let tab = targetBrowser.selectedTab = targetBrowser.addTab(aUrl);
   let linkedBrowser = tab.linkedBrowser;
 
-  linkedBrowser.addEventListener("load", function onLoad() {
-    linkedBrowser.removeEventListener("load", onLoad, true);
+  BrowserTestUtils.browserLoaded(linkedBrowser).then(function () {
     info("Tab added and finished loading: " + aUrl);
     deferred.resolve(tab);
-  }, true);
+  });
 
   return deferred.promise;
 }
 
 function removeTab(aTab, aWindow) {
   info("Removing tab.");
 
   let deferred = Promise.defer();

--- a/devtools/client/webide/test/head.js
+++ b/devtools/client/webide/test/head.js
@@ -162,21 +162,20 @@ function addTab(aUrl, aWindow) {
   let deferred = promise.defer();
   let targetWindow = aWindow || window;
   let targetBrowser = targetWindow.gBrowser;
 
   targetWindow.focus();
   let tab = targetBrowser.selectedTab = targetBrowser.addTab(aUrl);
   let linkedBrowser = tab.linkedBrowser;
 
-  linkedBrowser.addEventListener("load", function onLoad() {
-    linkedBrowser.removeEventListener("load", onLoad, true);
+  BrowserTestUtils.browserLoaded(linkedBrowser).then(function () {
     info("Tab added and finished loading: " + aUrl);
     deferred.resolve(tab);
-  }, true);
+  });
 
   return deferred.promise;
 }
 
 function removeTab(aTab, aWindow) {
   info("Removing tab.");
 
   let deferred = promise.defer();

--- a/devtools/server/tests/browser/browser_canvasframe_helper_04.js
+++ b/devtools/server/tests/browser/browser_canvasframe_helper_04.js
@@ -60,17 +60,17 @@ add_task(function* () {
 
   info("Synthesizing an event on the element");
   let onDocMouseDown = once(doc, "mousedown");
   synthesizeMouseDown(100, 100, doc.defaultView);
   yield onDocMouseDown;
   is(mouseDownHandled, 1, "The mousedown event was handled once before navigation");
 
   info("Navigating to a new page");
-  let loaded = once(gBrowser.selectedBrowser, "load", true);
+  let loaded = BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
   content.location = TEST_URL_2;
   yield loaded;
   doc = gBrowser.selectedBrowser.contentWindow.document;
 
   info("Try to access the element again");
   is(el.getAttribute("class"), "child-element",
     "The attribute is correct after navigation");
   is(el.getTextContent(), "test content",

--- a/devtools/server/tests/browser/head.js
+++ b/devtools/server/tests/browser/head.js
@@ -28,17 +28,17 @@ waitForExplicitFinish();
  * @return a promise that resolves to the new browser that the document
  *         is loaded in. Note that we cannot return the document
  *         directly, since this would be a CPOW in the e10s case,
  *         and Promises cannot be resolved with CPOWs (see bug 1233497).
  */
 var addTab = Task.async(function* (url) {
   info(`Adding a new tab with URL: ${url}`);
   let tab = gBrowser.selectedTab = gBrowser.addTab(url);
-  yield once(gBrowser.selectedBrowser, "load", true);
+  yield BrowserTestUtils.browserLoaded(tab.linkedBrowser);
 
   info(`Tab added and URL ${url} loaded`);
 
   return tab.linkedBrowser;
 });
 
 function* initAnimationsFrontForUrl(url) {
   const {AnimationsFront} = require("devtools/shared/fronts/animation");

--- a/dom/animation/test/css-animations/file_animation-id.html
+++ b/dom/animation/test/css-animations/file_animation-id.html
@@ -13,20 +13,12 @@ test(function(t) {
   div.style.animation = 'abc 100s';
   var animation = div.getAnimations()[0];
   assert_equals(animation.id, '', 'id for CSS Animation is initially empty');
   animation.id = 'anim'
 
   assert_equals(animation.id, 'anim', 'animation.id reflects the value set');
 }, 'Animation.id for CSS Animations');
 
-test(function(t) {
-  var div = addDiv(t);
-  var animation = div.animate({}, 100 * MS_PER_SEC);
-  assert_equals(animation.id, '', 'id for CSS Animation is initially empty');
-  animation.id = 'anim'
-
-  assert_equals(animation.id, 'anim', 'animation.id reflects the value set');
-}, 'Animation.id for CSS Animations');
 done();
 </script>
 </body>
 </html>

--- a/dom/animation/test/css-transitions/file_animation-cancel.html
+++ b/dom/animation/test/css-transitions/file_animation-cancel.html
@@ -1,106 +1,101 @@
 <!doctype html>
 <meta charset=utf-8>
 <script src="../testcommon.js"></script>
 <body>
 <script>
 'use strict';
 
-async_test(function(t) {
+promise_test(function(t) {
   var div = addDiv(t, { style: 'margin-left: 0px' });
   flushComputedStyle(div);
 
   div.style.transition = 'margin-left 100s';
   div.style.marginLeft = '1000px';
   flushComputedStyle(div);
 
   var animation = div.getAnimations()[0];
-  animation.ready.then(waitForFrame).then(t.step_func(function() {
+  return animation.ready.then(waitForFrame).then(function() {
     assert_not_equals(getComputedStyle(div).marginLeft, '1000px',
                       'transform style is animated before cancelling');
     animation.cancel();
     assert_equals(getComputedStyle(div).marginLeft, div.style.marginLeft,
                   'transform style is no longer animated after cancelling');
-    t.done();
-  }));
+  });
 }, 'Animated style is cleared after cancelling a running CSS transition');
 
-async_test(function(t) {
+promise_test(function(t) {
   var div = addDiv(t, { style: 'margin-left: 0px' });
   flushComputedStyle(div);
 
   div.style.transition = 'margin-left 100s';
   div.style.marginLeft = '1000px';
   flushComputedStyle(div);
 
-  div.addEventListener('transitionend', t.step_func(function() {
+  div.addEventListener('transitionend', function() {
     assert_unreached('Got unexpected end event on cancelled transition');
-  }));
+  });
 
   var animation = div.getAnimations()[0];
-  animation.ready.then(t.step_func(function() {
+  return animation.ready.then(function() {
     // Seek to just before the end then cancel
     animation.currentTime = 99.9 * 1000;
     animation.cancel();
 
     // Then wait a couple of frames and check that no event was dispatched
     return waitForAnimationFrames(2);
-  })).then(t.step_func(function() {
-    t.done();
-  }));
+  });
 }, 'Cancelled CSS transitions do not dispatch events');
 
-async_test(function(t) {
+promise_test(function(t) {
   var div = addDiv(t, { style: 'margin-left: 0px' });
   flushComputedStyle(div);
 
   div.style.transition = 'margin-left 100s';
   div.style.marginLeft = '1000px';
   flushComputedStyle(div);
 
   var animation = div.getAnimations()[0];
-  animation.ready.then(t.step_func(function() {
+  return animation.ready.then(function() {
     animation.cancel();
     assert_equals(getComputedStyle(div).marginLeft, '1000px',
                   'margin-left style is not animated after cancelling');
     animation.play();
     assert_equals(getComputedStyle(div).marginLeft, '0px',
                   'margin-left style is animated after re-starting transition');
     return animation.ready;
-  })).then(t.step_func(function() {
+  }).then(function() {
     assert_equals(animation.playState, 'running',
                   'Transition succeeds in running after being re-started');
-    t.done();
-  }));
+  });
 }, 'After cancelling a transition, it can still be re-used');
 
-async_test(function(t) {
+promise_test(function(t) {
   var div = addDiv(t, { style: 'margin-left: 0px' });
   flushComputedStyle(div);
 
   div.style.transition = 'margin-left 100s';
   div.style.marginLeft = '1000px';
   flushComputedStyle(div);
 
   var animation = div.getAnimations()[0];
-  animation.ready.then(t.step_func(function() {
+  return animation.ready.then(function() {
     animation.finish();
     animation.cancel();
     assert_equals(getComputedStyle(div).marginLeft, '1000px',
                   'margin-left style is not animated after cancelling');
     animation.play();
     assert_equals(getComputedStyle(div).marginLeft, '0px',
                   'margin-left style is animated after re-starting transition');
     return animation.ready;
-  })).then(t.step_func(function() {
+  }).then(function() {
     assert_equals(animation.playState, 'running',
                   'Transition succeeds in running after being re-started');
-    t.done();
-  }));
+  });
 }, 'After cancelling a finished transition, it can still be re-used');
 
 test(function(t) {
   var div = addDiv(t, { style: 'margin-left: 0px' });
   flushComputedStyle(div);
 
   div.style.transition = 'margin-left 100s';
   div.style.marginLeft = '1000px';
@@ -118,11 +113,25 @@ test(function(t) {
   assert_equals(getComputedStyle(div).marginLeft, '1000px',
                 'margin-left style is still not animated after updating'
                 + ' transition-duration');
   assert_equals(animation.playState, 'idle',
                 'Transition is still idle after updating transition-duration');
 }, 'After cancelling a transition, updating transition properties doesn\'t make'
    + ' it live again');
 
+test(function(t) {
+  var div = addDiv(t, { style: 'margin-left: 0px' });
+  flushComputedStyle(div);
+
+  div.style.transition = 'margin-left 100s';
+  div.style.marginLeft = '1000px';
+  flushComputedStyle(div);
+
+  var animation = div.getAnimations()[0];
+  div.style.display = 'none';
+  assert_equals(animation.playState, 'idle');
+  assert_equals(getComputedStyle(div).marginLeft, '1000px');
+}, 'Setting display:none on an element cancels its transitions');
+
 done();
 </script>
 </body>

--- a/dom/canvas/test/webgl-mochitest/mochitest.ini
+++ b/dom/canvas/test/webgl-mochitest/mochitest.ini
@@ -79,17 +79,17 @@ skip-if = android_version == '18' #Andro
 [test_uninit_data.html]
 [test_webgl_available.html]
 #[test_webgl_color_buffer_float.html]
 # We haven't cleaned up the Try results yet, but let's get this on the books first.
 [test_webgl_conformance.html]
 skip-if = toolkit == 'android' #bug 865443- seperate suite - the non_conf* tests pass except for one on armv6 tests
 [test_webgl_compressed_texture_es3.html]
 [test_webgl_disjoint_timer_query.html]
-fail-if = (os == 'win' && (os_version == '6.1' || os_version == '6.2'))
+fail-if = (os == 'win' && (os_version == '6.1' || os_version == '6.2' || os_version == '10.0'))
 [test_webgl_force_enable.html]
 [test_webgl_request_context.html]
 skip-if = toolkit == 'android' #bug 865443- seperate suite - the non_conf* tests pass except for one on armv6 tests
 [test_webgl_request_mismatch.html]
 skip-if = toolkit == 'android' #bug 865443- seperate suite - the non_conf* tests pass except for one on armv6 tests
 [test_webgl2_not_exposed.html]
 skip-if = toolkit == 'android' #bug 865443- seperate suite - the non_conf* tests pass except for one on armv6 tests
 [test_webgl2_invalidate_framebuffer.html]

--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -4336,17 +4336,17 @@ void HTMLMediaElement::MetadataLoaded(co
                "Video resolution must be known on 'loadedmetadata'");
   DispatchAsyncEvent(NS_LITERAL_STRING("loadedmetadata"));
   if (mDecoder && mDecoder->IsTransportSeekable() && mDecoder->IsMediaSeekable()) {
     ProcessMediaFragmentURI();
     mDecoder->SetFragmentEndTime(mFragmentEnd);
   }
   if (mIsEncrypted) {
     if (!mMediaSource && Preferences::GetBool("media.eme.mse-only", true)) {
-      DecodeError();
+      DecodeError(NS_ERROR_DOM_MEDIA_FATAL_ERR);
       return;
     }
 
 #ifdef MOZ_EME
     // Dispatch a distinct 'encrypted' event for each initData we have.
     for (const auto& initData : mPendingEncryptedInitData.mInitDatas) {
       DispatchEncrypted(initData.mInitData, initData.mType);
     }
@@ -4411,17 +4411,17 @@ void HTMLMediaElement::FirstFrameLoaded(
 void HTMLMediaElement::NetworkError()
 {
   if (mDecoder) {
     ShutdownDecoder();
   }
   Error(nsIDOMMediaError::MEDIA_ERR_NETWORK);
 }
 
-void HTMLMediaElement::DecodeError()
+void HTMLMediaElement::DecodeError(const MediaResult& aError)
 {
   nsAutoString src;
   GetCurrentSrc(src);
   const char16_t* params[] = { src.get() };
   ReportLoadError("MediaLoadDecodeError", params, ArrayLength(params));
 
   if (mDecoder) {
     ShutdownDecoder();
@@ -4435,45 +4435,50 @@ void HTMLMediaElement::DecodeError()
     mError = nullptr;
     if (mSourceLoadCandidate) {
       DispatchAsyncSourceError(mSourceLoadCandidate);
       QueueLoadFromSourceTask();
     } else {
       NS_WARNING("Should know the source we were loading from!");
     }
   } else {
-    Error(nsIDOMMediaError::MEDIA_ERR_DECODE);
+    Error(nsIDOMMediaError::MEDIA_ERR_DECODE, aError);
   }
 }
 
 bool HTMLMediaElement::HasError() const
 {
   return GetError();
 }
 
 void HTMLMediaElement::LoadAborted()
 {
   Error(nsIDOMMediaError::MEDIA_ERR_ABORTED);
 }
 
-void HTMLMediaElement::Error(uint16_t aErrorCode)
+void HTMLMediaElement::Error(uint16_t aErrorCode,
+                             const MediaResult& aErrorDetails)
 {
   NS_ASSERTION(aErrorCode == nsIDOMMediaError::MEDIA_ERR_DECODE ||
                aErrorCode == nsIDOMMediaError::MEDIA_ERR_NETWORK ||
                aErrorCode == nsIDOMMediaError::MEDIA_ERR_ABORTED,
                "Only use nsIDOMMediaError codes!");
 
   // Since we have multiple paths calling into DecodeError, e.g.
   // MediaKeys::Terminated and EMEH264Decoder::Error. We should take the 1st
   // one only in order not to fire multiple 'error' events.
   if (mError) {
     return;
   }
-
-  mError = new MediaError(this, aErrorCode);
+  nsCString message;
+  if (NS_FAILED(aErrorDetails)) {
+    message = aErrorDetails.Description();
+  }
+  mError = new MediaError(this, aErrorCode, message);
+
   DispatchAsyncEvent(NS_LITERAL_STRING("error"));
   if (mReadyState == nsIDOMHTMLMediaElement::HAVE_NOTHING) {
     ChangeNetworkState(nsIDOMHTMLMediaElement::NETWORK_EMPTY);
     DispatchAsyncEvent(NS_LITERAL_STRING("emptied"));
   } else {
     ChangeNetworkState(nsIDOMHTMLMediaElement::NETWORK_IDLE);
   }
   ChangeDelayLoadStatus(false);

--- a/dom/html/HTMLMediaElement.h
+++ b/dom/html/HTMLMediaElement.h
@@ -174,17 +174,17 @@ public:
   virtual void FirstFrameLoaded() final override;
 
   // Called by the video decoder object, on the main thread,
   // when the resource has a network error during loading.
   virtual void NetworkError() final override;
 
   // Called by the video decoder object, on the main thread, when the
   // resource has a decode error during metadata loading or decoding.
-  virtual void DecodeError() final override;
+  virtual void DecodeError(const MediaResult& aError) final override;
 
   // Return true if error attribute is not null.
   virtual bool HasError() const final override;
 
   // Called by the video decoder object, on the main thread, when the
   // resource load has been cancelled.
   virtual void LoadAborted() final override;
 
@@ -1111,17 +1111,17 @@ protected:
    * Dispatches an error event to a child source element.
    */
   void DispatchAsyncSourceError(nsIContent* aSourceElement);
 
   /**
    * Resets the media element for an error condition as per aErrorCode.
    * aErrorCode must be one of nsIDOMHTMLMediaError codes.
    */
-  void Error(uint16_t aErrorCode);
+  void Error(uint16_t aErrorCode, const MediaResult& aErrorDetails = NS_OK);
 
   /**
    * Returns the URL spec of the currentSrc.
    **/
   void GetCurrentSpec(nsCString& aString);
 
   /**
    * Process any media fragment entries in the URI

--- a/dom/html/MediaError.cpp
+++ b/dom/html/MediaError.cpp
@@ -16,30 +16,38 @@ NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaErr
 NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaError)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaError)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsIDOMMediaError)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMMediaError)
 NS_INTERFACE_MAP_END
 
-MediaError::MediaError(HTMLMediaElement* aParent, uint16_t aCode)
+MediaError::MediaError(HTMLMediaElement* aParent, uint16_t aCode,
+                       const nsACString& aMessage)
   : mParent(aParent)
   , mCode(aCode)
+  , mMessage(aMessage)
 {
 }
 
 NS_IMETHODIMP MediaError::GetCode(uint16_t* aCode)
 {
   if (aCode)
     *aCode = Code();
 
   return NS_OK;
 }
 
+NS_IMETHODIMP MediaError::GetMessage(nsAString& aResult)
+{
+  CopyUTF8toUTF16(mMessage, aResult);
+  return NS_OK;
+}
+
 JSObject*
 MediaError::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 {
   return MediaErrorBinding::Wrap(aCx, this, aGivenProto);
 }
 
 } // namespace dom
 } // namespace mozilla

--- a/dom/html/MediaError.h
+++ b/dom/html/MediaError.h
@@ -17,17 +17,18 @@ namespace mozilla {
 namespace dom {
 
 class MediaError final : public nsIDOMMediaError,
                          public nsWrapperCache
 {
   ~MediaError() {}
 
 public:
-  MediaError(HTMLMediaElement* aParent, uint16_t aCode);
+  MediaError(HTMLMediaElement* aParent, uint16_t aCode,
+             const nsACString& aMessage = nsCString());
 
   // nsISupports
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaError)
 
   // nsIDOMMediaError
   NS_DECL_NSIDOMMEDIAERROR
 
@@ -43,14 +44,16 @@ public:
     return mCode;
   }
 
 private:
   RefPtr<HTMLMediaElement> mParent;
 
   // Error code
   const uint16_t mCode;
+  // Error details;
+  const nsCString mMessage;
 };
 
 } // namespace dom
 } // namespace mozilla
 
 #endif // mozilla_dom_MediaError_h

--- a/dom/interfaces/html/nsIDOMMediaError.idl
+++ b/dom/interfaces/html/nsIDOMMediaError.idl
@@ -7,21 +7,23 @@
 
 [uuid(7bd8c29f-8a76-453f-9373-79f820f2dc01)]
 interface nsIDOMMediaError : nsISupports
 {
   /* The download of the media resource was aborted by
      the user agent at the user's requet */
   const unsigned short MEDIA_ERR_ABORTED = 1;
 
-  /* A network error of some description caused the 
+  /* A network error of some description caused the
      user agent to stop downloading the media resource */
   const unsigned short MEDIA_ERR_NETWORK = 2;
 
-  /* An error of some description occurred while decoding 
+  /* An error of some description occurred while decoding
      the media resource */
   const unsigned short MEDIA_ERR_DECODE  = 3;
 
   /* No suitable media resource could be found */
   const unsigned short MEDIA_ERR_SRC_NOT_SUPPORTED = 4;
 
   readonly attribute unsigned short code;
+
+  readonly attribute DOMString message;
 };

--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -1307,24 +1307,41 @@ StartMacOSContentSandbox()
   }
 
   nsAutoCString tempDirPath;
   rv = tempDir->GetNativePath(tempDirPath);
   if (NS_FAILED(rv)) {
     MOZ_CRASH("Failed to get NS_OS_TEMP_DIR path");
   }
 
+  nsCOMPtr<nsIFile> profileDir;
+  ContentChild::GetSingleton()->GetProfileDir(getter_AddRefs(profileDir));
+  nsCString profileDirPath;
+  if (profileDir) {
+    rv = profileDir->GetNativePath(profileDirPath);
+    if (NS_FAILED(rv) || profileDirPath.IsEmpty()) {
+      MOZ_CRASH("Failed to get profile path");
+    }
+  }
+
   MacSandboxInfo info;
   info.type = MacSandboxType_Content;
   info.level = info.level = sandboxLevel;
   info.appPath.assign(appPath.get());
   info.appBinaryPath.assign(appBinaryPath.get());
   info.appDir.assign(appDir.get());
   info.appTempDir.assign(tempDirPath.get());
 
+  if (profileDir) {
+    info.hasSandboxedProfile = true;
+    info.profileDir.assign(profileDirPath.get());
+  } else {
+    info.hasSandboxedProfile = false;
+  }
+
   std::string err;
   if (!mozilla::StartMacSandbox(info, err)) {
     NS_WARNING(err.c_str());
     MOZ_CRASH("sandbox_init() failed");
   }
 
   return true;
 }

--- a/dom/ipc/ContentChild.h
+++ b/dom/ipc/ContentChild.h
@@ -16,16 +16,19 @@
 #include "nsHashKeys.h"
 #include "nsIObserver.h"
 #include "nsTHashtable.h"
 #include "nsRefPtrHashtable.h"
 
 #include "nsWeakPtr.h"
 #include "nsIWindowProvider.h"
 
+#if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
+#include "nsIFile.h"
+#endif
 
 struct ChromePackage;
 class nsIObserver;
 struct SubstitutionMapping;
 struct OverrideMapping;
 class nsIDomainPolicy;
 
 namespace mozilla {
@@ -109,16 +112,29 @@ public:
   }
 
   void SetProcessName(const nsAString& aName, bool aDontOverride = false);
 
   void GetProcessName(nsAString& aName) const;
 
   void GetProcessName(nsACString& aName) const;
 
+#if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
+  void GetProfileDir(nsIFile** aProfileDir) const
+  {
+    *aProfileDir = mProfileDir;
+    NS_IF_ADDREF(*aProfileDir);
+  }
+
+  void SetProfileDir(nsIFile* aProfileDir)
+  {
+    mProfileDir = aProfileDir;
+  }
+#endif
+
   bool IsAlive() const;
 
   bool IsShuttingDown() const;
 
   static void AppendProcessId(nsACString& aName);
 
   ContentBridgeParent* GetLastBridge()
   {
@@ -676,16 +692,20 @@ private:
   bool mIsAlive;
   nsString mProcessName;
 
   static ContentChild* sSingleton;
 
   nsCOMPtr<nsIDomainPolicy> mPolicy;
   nsCOMPtr<nsITimer> mForceKillTimer;
 
+#if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
+  nsCOMPtr<nsIFile> mProfileDir;
+#endif
+
   // Hashtable to keep track of the pending GetFilesHelper objects.
   // This GetFilesHelperChild objects are removed when RecvGetFilesResponse is
   // received.
   nsRefPtrHashtable<nsIDHashKey, GetFilesHelperChild> mGetFilesPendingRequests;
 
   bool mShuttingDown;
 
   DISALLOW_EVIL_CONSTRUCTORS(ContentChild);

--- a/dom/ipc/ContentProcess.cpp
+++ b/dom/ipc/ContentProcess.cpp
@@ -109,26 +109,45 @@ SetUpSandboxEnvironment()
 #endif
 
 void
 ContentProcess::SetAppDir(const nsACString& aPath)
 {
   mXREEmbed.SetAppDir(aPath);
 }
 
+#if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
+void
+ContentProcess::SetProfile(const nsACString& aProfile)
+{
+  bool flag;
+  nsresult rv =
+    XRE_GetFileFromPath(aProfile.BeginReading(), getter_AddRefs(mProfileDir));
+  if (NS_FAILED(rv) ||
+      NS_FAILED(mProfileDir->Exists(&flag)) || !flag) {
+    NS_WARNING("Invalid profile directory passed to content process.");
+    mProfileDir = nullptr;
+  }
+}
+#endif
+
 bool
 ContentProcess::Init()
 {
     mContent.Init(IOThreadChild::message_loop(),
                   ParentPid(),
                   IOThreadChild::channel());
     mXREEmbed.Start();
     mContent.InitXPCOM();
     mContent.InitGraphicsDeviceData();
 
+#if (defined(XP_MACOSX)) && defined(MOZ_CONTENT_SANDBOX)
+    mContent.SetProfileDir(mProfileDir);
+#endif
+
 #if (defined(XP_WIN) || defined(XP_MACOSX)) && defined(MOZ_CONTENT_SANDBOX)
     SetUpSandboxEnvironment();
 #endif
 
     return true;
 }
 
 // Note: CleanUp() never gets called in non-debug builds because we exit early

--- a/dom/ipc/ContentProcess.h
+++ b/dom/ipc/ContentProcess.h
@@ -34,19 +34,28 @@ public:
   ~ContentProcess()
   { }
 
   virtual bool Init() override;
   virtual void CleanUp() override;
 
   void SetAppDir(const nsACString& aPath);
 
+#if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
+  void SetProfile(const nsACString& aProfile);
+#endif
+
 private:
   ContentChild mContent;
   mozilla::ipc::ScopedXREEmbed mXREEmbed;
+
+#if defined(XP_MACOSX) && defined(MOZ_CONTENT_SANDBOX)
+  nsCOMPtr<nsIFile> mProfileDir;
+#endif
+
 #if defined(XP_WIN)
   // This object initializes and configures COM.
   mozilla::mscom::MainThreadRuntime mCOMRuntime;
 #endif
 
   DISALLOW_EVIL_CONSTRUCTORS(ContentProcess);
 };
 

--- a/dom/media/ADTSDemuxer.cpp
+++ b/dom/media/ADTSDemuxer.cpp
@@ -313,17 +313,17 @@ ADTSDemuxer::InitInternal()
 
 RefPtr<ADTSDemuxer::InitPromise>
 ADTSDemuxer::Init()
 {
   if (!InitInternal()) {
     ADTSLOG("Init() failure: waiting for data");
 
     return InitPromise::CreateAndReject(
-      DemuxerFailureReason::DEMUXER_ERROR, __func__);
+      NS_ERROR_DOM_MEDIA_METADATA_ERR, __func__);
   }
 
   ADTSLOG("Init() successful");
   return InitPromise::CreateAndResolve(NS_OK, __func__);
 }
 
 bool
 ADTSDemuxer::HasTrackType(TrackInfo::TrackType aType) const
@@ -510,20 +510,17 @@ RefPtr<ADTSTrackDemuxer::SamplesPromise>
 ADTSTrackDemuxer::GetSamples(int32_t aNumSamples)
 {
   ADTSLOGV("GetSamples(%d) Begin mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64
           " mFrameIndex=%" PRId64 " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d "
           "mSamplesPerSecond=%d mChannels=%d",
           aNumSamples, mOffset, mNumParsedFrames, mFrameIndex, mTotalFrameLen,
           mSamplesPerFrame, mSamplesPerSecond, mChannels);
 
-  if (!aNumSamples) {
-    return SamplesPromise::CreateAndReject(
-      DemuxerFailureReason::DEMUXER_ERROR, __func__);
-  }
+  MOZ_ASSERT(aNumSamples);
 
   RefPtr<SamplesHolder> frames = new SamplesHolder();
 
   while (aNumSamples--) {
     RefPtr<MediaRawData> frame(GetNextFrame(FindNextFrame()));
     if (!frame)
       break;
 
@@ -535,17 +532,17 @@ ADTSTrackDemuxer::GetSamples(int32_t aNu
           " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d mSamplesPerSecond=%d "
           "mChannels=%d",
           frames->mSamples.Length(), aNumSamples, mOffset, mNumParsedFrames,
           mFrameIndex, mTotalFrameLen, mSamplesPerFrame, mSamplesPerSecond,
           mChannels);
 
   if (frames->mSamples.IsEmpty()) {
     return SamplesPromise::CreateAndReject(
-      DemuxerFailureReason::END_OF_STREAM, __func__);
+      NS_ERROR_DOM_MEDIA_END_OF_STREAM, __func__);
   }
 
   return SamplesPromise::CreateAndResolve(frames, __func__);
 }
 
 void
 ADTSTrackDemuxer::Reset()
 {
@@ -557,17 +554,17 @@ ADTSTrackDemuxer::Reset()
   FastSeek(media::TimeUnit());
 }
 
 RefPtr<ADTSTrackDemuxer::SkipAccessPointPromise>
 ADTSTrackDemuxer::SkipToNextRandomAccessPoint(media::TimeUnit aTimeThreshold)
 {
   // Will not be called for audio-only resources.
   return SkipAccessPointPromise::CreateAndReject(
-    SkipFailureHolder(DemuxerFailureReason::DEMUXER_ERROR, 0), __func__);
+    SkipFailureHolder(NS_ERROR_DOM_MEDIA_DEMUXER_ERR, 0), __func__);
 }
 
 int64_t
 ADTSTrackDemuxer::GetResourceOffset() const
 {
   return mOffset;
 }
 

--- a/dom/media/AccurateSeekTask.cpp
+++ b/dom/media/AccurateSeekTask.cpp
@@ -56,17 +56,17 @@ AccurateSeekTask::~AccurateSeekTask()
 }
 
 void
 AccurateSeekTask::Discard()
 {
   AssertOwnerThread();
 
   // Disconnect MDSM.
-  RejectIfExist(__func__);
+  RejectIfExist(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
 
   // Disconnect MediaDecoderReaderWrapper.
   mSeekRequest.DisconnectIfExists();
   CancelCallbacks();
 
   mIsDiscarded = true;
 }
 
@@ -115,17 +115,17 @@ AccurateSeekTask::DropAudioUpToSeekTarge
 {
   AssertOwnerThread();
 
   RefPtr<AudioData> audio(aSample->As<AudioData>());
   MOZ_ASSERT(audio && mTarget.IsAccurate());
 
   CheckedInt64 sampleDuration = FramesToUsecs(audio->mFrames, mAudioRate);
   if (!sampleDuration.isValid()) {
-    return NS_ERROR_FAILURE;
+    return NS_ERROR_DOM_MEDIA_OVERFLOW_ERR;
   }
 
   if (audio->mTime + sampleDuration.value() <= mTarget.GetTime().ToMicroseconds()) {
     // Our seek target lies after the frames in this AudioData. Don't
     // push it onto the audio queue, and keep decoding forwards.
     return NS_OK;
   }
 
@@ -149,17 +149,17 @@ AccurateSeekTask::DropAudioUpToSeekTarge
   NS_ASSERTION(mTarget.GetTime().ToMicroseconds() >= audio->mTime,
                "Target must at or be after data start.");
   NS_ASSERTION(mTarget.GetTime().ToMicroseconds() < audio->mTime + sampleDuration.value(),
                "Data must end after target.");
 
   CheckedInt64 framesToPrune =
     UsecsToFrames(mTarget.GetTime().ToMicroseconds() - audio->mTime, mAudioRate);
   if (!framesToPrune.isValid()) {
-    return NS_ERROR_FAILURE;
+    return NS_ERROR_DOM_MEDIA_OVERFLOW_ERR;
   }
   if (framesToPrune.value() > audio->mFrames) {
     // We've messed up somehow. Don't try to trim frames, the |frames|
     // variable below will overflow.
     DECODER_WARN("Can't prune more frames that we have!");
     return NS_ERROR_FAILURE;
   }
   uint32_t frames = audio->mFrames - static_cast<uint32_t>(framesToPrune.value());
@@ -169,17 +169,17 @@ AccurateSeekTask::DropAudioUpToSeekTarge
     return NS_ERROR_OUT_OF_MEMORY;
   }
 
   memcpy(audioData.get(),
          audio->mAudioData.get() + (framesToPrune.value() * channels),
          frames * channels * sizeof(AudioDataValue));
   CheckedInt64 duration = FramesToUsecs(frames, mAudioRate);
   if (!duration.isValid()) {
-    return NS_ERROR_FAILURE;
+    return NS_ERROR_DOM_MEDIA_OVERFLOW_ERR;
   }
   RefPtr<AudioData> data(new AudioData(audio->mOffset,
                                        mTarget.GetTime().ToMicroseconds(),
                                        duration.value(),
                                        frames,
                                        Move(audioData),
                                        channels,
                                        audio->mRate));
@@ -255,17 +255,17 @@ AccurateSeekTask::OnSeekResolved(media::
 
 void
 AccurateSeekTask::OnSeekRejected(nsresult aResult)
 {
   AssertOwnerThread();
 
   mSeekRequest.Complete();
   MOZ_ASSERT(NS_FAILED(aResult), "Cancels should also disconnect mSeekRequest");
-  RejectIfExist(__func__);
+  RejectIfExist(aResult, __func__);
 }
 
 void
 AccurateSeekTask::AdjustFastSeekIfNeeded(MediaData* aSample)
 {
   AssertOwnerThread();
   if (mTarget.IsFast() &&
       mTarget.GetTime() > mCurrentTimeBeforeSeek &&
@@ -303,81 +303,82 @@ AccurateSeekTask::OnAudioDecoded(MediaDa
   }
 
   AdjustFastSeekIfNeeded(audio);
 
   if (mTarget.IsFast()) {
     // Non-precise seek; we can stop the seek at the first sample.
     mSeekedAudioData = audio;
     mDoneAudioSeeking = true;
-  } else if (NS_FAILED(DropAudioUpToSeekTarget(audio))) {
-    CancelCallbacks();
-    RejectIfExist(__func__);
-    return;
+  } else {
+    nsresult rv = DropAudioUpToSeekTarget(audio);
+    if (NS_FAILED(rv)) {
+      CancelCallbacks();
+      RejectIfExist(rv, __func__);
+      return;
+    }
   }
 
   if (!mDoneAudioSeeking) {
     RequestAudioData();
     return;
   }
   MaybeFinishSeek();
 }
 
 void
 AccurateSeekTask::OnNotDecoded(MediaData::Type aType,
-                               MediaDecoderReader::NotDecodedReason aReason)
+                               const MediaResult& aError)
 {
   AssertOwnerThread();
   MOZ_ASSERT(!mSeekTaskPromise.IsEmpty(), "Seek shouldn't be finished");
 
-  SAMPLE_LOG("OnNotDecoded type=%d reason=%u", aType, aReason);
+  SAMPLE_LOG("OnNotDecoded type=%d reason=%u", aType, aError.Code());
 
   // Ignore pending requests from video-only seek.
   if (aType == MediaData::AUDIO_DATA && mTarget.IsVideoOnly()) {
     return;
   }
 
-  if (aReason == MediaDecoderReader::DECODE_ERROR) {
-    // If this is a decode error, delegate to the generic error path.
-    CancelCallbacks();
-    RejectIfExist(__func__);
-    return;
-  }
-
   // If the decoder is waiting for data, we tell it to call us back when the
   // data arrives.
-  if (aReason == MediaDecoderReader::WAITING_FOR_DATA) {
+  if (aError == NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA) {
     mReader->WaitForData(aType);
     return;
   }
 
-  if (aReason == MediaDecoderReader::CANCELED) {
+  if (aError == NS_ERROR_DOM_MEDIA_CANCELED) {
     if (aType == MediaData::AUDIO_DATA) {
       RequestAudioData();
     } else {
       RequestVideoData();
     }
     return;
   }
 
-  if (aReason == MediaDecoderReader::END_OF_STREAM) {
+  if (aError == NS_ERROR_DOM_MEDIA_END_OF_STREAM) {
     if (aType == MediaData::AUDIO_DATA) {
       mIsAudioQueueFinished = true;
       mDoneAudioSeeking = true;
     } else {
       mIsVideoQueueFinished = true;
       mDoneVideoSeeking = true;
       if (mFirstVideoFrameAfterSeek) {
         // Hit the end of stream. Move mFirstVideoFrameAfterSeek into
         // mSeekedVideoData so we have something to display after seeking.
         mSeekedVideoData = mFirstVideoFrameAfterSeek.forget();
       }
     }
     MaybeFinishSeek();
+    return;
   }
+
+  // This is a decode error, delegate to the generic error path.
+  CancelCallbacks();
+  RejectIfExist(aError, __func__);
 }
 
 void
 AccurateSeekTask::OnVideoDecoded(MediaData* aVideoSample)
 {
   AssertOwnerThread();
   MOZ_ASSERT(!mSeekTaskPromise.IsEmpty(), "Seek shouldn't be finished");
 
@@ -390,20 +391,23 @@ AccurateSeekTask::OnVideoDecoded(MediaDa
   SAMPLE_LOG("OnVideoDecoded [%lld,%lld]", video->mTime, video->GetEndTime());
 
   AdjustFastSeekIfNeeded(video);
 
   if (mTarget.IsFast()) {
     // Non-precise seek. We can stop the seek at the first sample.
     mSeekedVideoData = video;
     mDoneVideoSeeking = true;
-  } else if (NS_FAILED(DropVideoUpToSeekTarget(video.get()))) {
-    CancelCallbacks();
-    RejectIfExist(__func__);
-    return;
+  } else {
+    nsresult rv = DropVideoUpToSeekTarget(video.get());
+    if (NS_FAILED(rv)) {
+      CancelCallbacks();
+      RejectIfExist(rv, __func__);
+      return;
+    }
   }
 
   if (!mDoneVideoSeeking) {
     RequestVideoData();
     return;
   }
   MaybeFinishSeek();
 }
@@ -414,28 +418,28 @@ AccurateSeekTask::SetCallbacks()
   AssertOwnerThread();
 
   mAudioCallback = mReader->AudioCallback().Connect(
     OwnerThread(), [this] (AudioCallbackData aData) {
     if (aData.is<MediaData*>()) {
       OnAudioDecoded(aData.as<MediaData*>());
     } else {
       OnNotDecoded(MediaData::AUDIO_DATA,
-        aData.as<MediaDecoderReader::NotDecodedReason>());
+        aData.as<MediaResult>());
     }
   });
 
   mVideoCallback = mReader->VideoCallback().Connect(
     OwnerThread(), [this] (VideoCallbackData aData) {
     typedef Tuple<MediaData*, TimeStamp> Type;
     if (aData.is<Type>()) {
       OnVideoDecoded(Get<0>(aData.as<Type>()));
     } else {
       OnNotDecoded(MediaData::VIDEO_DATA,
-        aData.as<MediaDecoderReader::NotDecodedReason>());
+        aData.as<MediaResult>());
     }
   });
 
   mAudioWaitCallback = mReader->AudioWaitCallback().Connect(
     OwnerThread(), [this] (WaitCallbackData aData) {
     // Ignore pending requests from video-only seek.
     if (mTarget.IsVideoOnly()) {
       return;

--- a/dom/media/AccurateSeekTask.h
+++ b/dom/media/AccurateSeekTask.h
@@ -45,17 +45,17 @@ private:
   void OnSeekResolved(media::TimeUnit);
 
   void OnSeekRejected(nsresult aResult);
 
   void OnAudioDecoded(MediaData* aAudioSample);
 
   void OnVideoDecoded(MediaData* aVideoSample);
 
-  void OnNotDecoded(MediaData::Type, MediaDecoderReader::NotDecodedReason);
+  void OnNotDecoded(MediaData::Type, const MediaResult&);
 
   void SetCallbacks();
 
   void CancelCallbacks();
 
   void AdjustFastSeekIfNeeded(MediaData* aSample);
 
   /*

--- a/dom/media/Benchmark.cpp
+++ b/dom/media/Benchmark.cpp
@@ -164,17 +164,17 @@ BenchmarkPlayback::DemuxSamples()
       mTrackDemuxer =
         mDemuxer->GetTrackDemuxer(TrackInfo::kVideoTrack, 0);
       if (!mTrackDemuxer) {
         MainThreadShutdown();
         return;
       }
       DemuxNextSample();
     },
-    [this, ref](DemuxerFailureReason aReason) { MainThreadShutdown(); });
+    [this, ref](const MediaResult& aError) { MainThreadShutdown(); });
 }
 
 void
 BenchmarkPlayback::DemuxNextSample()
 {
   MOZ_ASSERT(OnThread());
 
   RefPtr<Benchmark> ref(mMainThreadState);
@@ -185,19 +185,19 @@ BenchmarkPlayback::DemuxNextSample()
       mSamples.AppendElements(Move(aHolder->mSamples));
       if (ref->mParameters.mStopAtFrame &&
           mSamples.Length() == (size_t)ref->mParameters.mStopAtFrame.ref()) {
         InitDecoder(Move(*mTrackDemuxer->GetInfo()));
       } else {
         Dispatch(NS_NewRunnableFunction([this, ref]() { DemuxNextSample(); }));
       }
     },
-    [this, ref](DemuxerFailureReason aReason) {
-      switch (aReason) {
-        case DemuxerFailureReason::END_OF_STREAM:
+    [this, ref](const MediaResult& aError) {
+      switch (aError.Code()) {
+        case NS_ERROR_DOM_MEDIA_END_OF_STREAM:
           InitDecoder(Move(*mTrackDemuxer->GetInfo()));
           break;
         default:
           MainThreadShutdown();
       }
     });
 }
 
@@ -213,17 +213,17 @@ BenchmarkPlayback::InitDecoder(TrackInfo
     return;
   }
   RefPtr<Benchmark> ref(mMainThreadState);
   mDecoder->Init()->Then(
     Thread(), __func__,
     [this, ref](TrackInfo::TrackType aTrackType) {
       InputExhausted();
     },
-    [this, ref](MediaDataDecoder::DecoderFailureReason aReason) {
+    [this, ref](MediaResult aError) {
       MainThreadShutdown();
     });
 }
 
 void
 BenchmarkPlayback::MainThreadShutdown()
 {
   MOZ_ASSERT(OnThread());
@@ -276,17 +276,17 @@ BenchmarkPlayback::Output(MediaData* aDa
       ref->Dispatch(NS_NewRunnableFunction([ref, decodeFps]() {
         ref->ReturnResult(decodeFps);
       }));
     }
   }));
 }
 
 void
-BenchmarkPlayback::Error(MediaDataDecoderError aError)
+BenchmarkPlayback::Error(const MediaResult& aError)
 {
   RefPtr<Benchmark> ref(mMainThreadState);
   Dispatch(NS_NewRunnableFunction([this, ref]() {  MainThreadShutdown(); }));
 }
 
 void
 BenchmarkPlayback::InputExhausted()
 {

--- a/dom/media/Benchmark.h
+++ b/dom/media/Benchmark.h
@@ -27,17 +27,17 @@ class BenchmarkPlayback : public QueueOb
   void DemuxSamples();
   void DemuxNextSample();
   void MainThreadShutdown();
   void InitDecoder(TrackInfo&& aInfo);
 
   // MediaDataDecoderCallback
   // Those methods are called on the MediaDataDecoder's task queue.
   void Output(MediaData* aData) override;
-  void Error(MediaDataDecoderError aError) override;
+  void Error(const MediaResult& aError) override;
   void InputExhausted() override;
   void DrainComplete() override;
   bool OnReaderTaskQueue() override;
 
   Atomic<Benchmark*> mMainThreadState;
 
   RefPtr<TaskQueue> mDecoderTaskQueue;
   RefPtr<MediaDataDecoder> mDecoder;

--- a/dom/media/MP3Demuxer.cpp
+++ b/dom/media/MP3Demuxer.cpp
@@ -50,17 +50,17 @@ MP3Demuxer::InitInternal() {
 }
 
 RefPtr<MP3Demuxer::InitPromise>
 MP3Demuxer::Init() {
   if (!InitInternal()) {
     MP3LOG("MP3Demuxer::Init() failure: waiting for data");
 
     return InitPromise::CreateAndReject(
-      DemuxerFailureReason::DEMUXER_ERROR, __func__);
+      NS_ERROR_DOM_MEDIA_METADATA_ERR, __func__);
   }
 
   MP3LOG("MP3Demuxer::Init() successful");
   return InitPromise::CreateAndResolve(NS_OK, __func__);
 }
 
 bool
 MP3Demuxer::HasTrackType(TrackInfo::TrackType aType) const {
@@ -271,17 +271,17 @@ MP3TrackDemuxer::GetSamples(int32_t aNum
   MP3LOGV("GetSamples(%d) Begin mOffset=%" PRIu64 " mNumParsedFrames=%" PRIu64
           " mFrameIndex=%" PRId64 " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d "
           "mSamplesPerSecond=%d mChannels=%d",
           aNumSamples, mOffset, mNumParsedFrames, mFrameIndex, mTotalFrameLen,
           mSamplesPerFrame, mSamplesPerSecond, mChannels);
 
   if (!aNumSamples) {
     return SamplesPromise::CreateAndReject(
-        DemuxerFailureReason::DEMUXER_ERROR, __func__);
+        NS_ERROR_DOM_MEDIA_DEMUXER_ERR, __func__);
   }
 
   RefPtr<SamplesHolder> frames = new SamplesHolder();
 
   while (aNumSamples--) {
     RefPtr<MediaRawData> frame(GetNextFrame(FindNextFrame()));
     if (!frame) {
       break;
@@ -295,34 +295,34 @@ MP3TrackDemuxer::GetSamples(int32_t aNum
           " mTotalFrameLen=%" PRIu64 " mSamplesPerFrame=%d mSamplesPerSecond=%d "
           "mChannels=%d",
           frames->mSamples.Length(), aNumSamples, mOffset, mNumParsedFrames,
           mFrameIndex, mTotalFrameLen, mSamplesPerFrame, mSamplesPerSecond,
           mChannels);
 
   if (frames->mSamples.IsEmpty()) {
     return SamplesPromise::CreateAndReject(
-        DemuxerFailureReason::END_OF_STREAM, __func__);
+        NS_ERROR_DOM_MEDIA_END_OF_STREAM, __func__);
   }
   return SamplesPromise::CreateAndResolve(frames, __func__);
 }
 
 void
 MP3TrackDemuxer::Reset() {
   MP3LOG("Reset()");
 
   FastSeek(TimeUnit());
   mParser.Reset();
 }
 
 RefPtr<MP3TrackDemuxer::SkipAccessPointPromise>
 MP3TrackDemuxer::SkipToNextRandomAccessPoint(TimeUnit aTimeThreshold) {
   // Will not be called for audio-only resources.
   return SkipAccessPointPromise::CreateAndReject(
-    SkipFailureHolder(DemuxerFailureReason::DEMUXER_ERROR, 0), __func__);
+    SkipFailureHolder(NS_ERROR_DOM_MEDIA_DEMUXER_ERR, 0), __func__);
 }
 
 int64_t
 MP3TrackDemuxer::GetResourceOffset() const {
   return mOffset;
 }
 
 TimeIntervals

--- a/dom/media/MediaDataDemuxer.h
+++ b/dom/media/MediaDataDemuxer.h
@@ -7,46 +7,37 @@
 #if !defined(MediaDataDemuxer_h)
 #define MediaDataDemuxer_h
 
 #include "mozilla/MozPromise.h"
 #include "mozilla/UniquePtr.h"
 
 #include "MediaData.h"
 #include "MediaInfo.h"
+#include "MediaResult.h"
 #include "TimeUnits.h"
 #include "nsISupportsImpl.h"
 #include "mozilla/RefPtr.h"
 #include "nsTArray.h"
 
 namespace mozilla {
 
 class MediaTrackDemuxer;
 class TrackMetadataHolder;
 
-enum class DemuxerFailureReason : int8_t
-{
-  WAITING_FOR_DATA,
-  END_OF_STREAM,
-  DEMUXER_ERROR,
-  CANCELED,
-  SHUTDOWN,
-};
-
-
 // Allows reading the media data: to retrieve the metadata and demux samples.
 // MediaDataDemuxer isn't designed to be thread safe.
 // When used by the MediaFormatDecoder, care is taken to ensure that the demuxer
 // will never be called from more than one thread at once.
 class MediaDataDemuxer
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaDataDemuxer)
 
-  typedef MozPromise<nsresult, DemuxerFailureReason, /* IsExclusive = */ true> InitPromise;
+  typedef MozPromise<nsresult, MediaResult, /* IsExclusive = */ true> InitPromise;
 
   // Initializes the demuxer. Other methods cannot be called unless
   // initialization has completed and succeeded.
   // Typically a demuxer will wait to parse the metadata before resolving the
   // promise. The promise must not be resolved until sufficient data is
   // supplied. For example, an incomplete metadata would cause the promise to be
   // rejected should no more data be coming, while the demuxer would wait
   // otherwise.
@@ -115,26 +106,26 @@ public:
     NS_INLINE_DECL_THREADSAFE_REFCOUNTING(SamplesHolder)
     nsTArray<RefPtr<MediaRawData>> mSamples;
   private:
     ~SamplesHolder() {}
   };
 
   class SkipFailureHolder {
   public:
-    SkipFailureHolder(DemuxerFailureReason aFailure, uint32_t aSkipped)
+    SkipFailureHolder(const MediaResult& aFailure, uint32_t aSkipped)
       : mFailure(aFailure)
       , mSkipped(aSkipped)
     {}
-    DemuxerFailureReason mFailure;
+    MediaResult mFailure;
     uint32_t mSkipped;
   };
 
-  typedef MozPromise<media::TimeUnit, DemuxerFailureReason, /* IsExclusive = */ true> SeekPromise;
-  typedef MozPromise<RefPtr<SamplesHolder>, DemuxerFailureReason, /* IsExclusive = */ true> SamplesPromise;
+  typedef MozPromise<media::TimeUnit, MediaResult, /* IsExclusive = */ true> SeekPromise;
+  typedef MozPromise<RefPtr<SamplesHolder>, MediaResult, /* IsExclusive = */ true> SamplesPromise;
   typedef MozPromise<uint32_t, SkipFailureHolder, /* IsExclusive = */ true> SkipAccessPointPromise;
 
   // Returns the TrackInfo (a.k.a Track Description) for this track.
   // The TrackInfo returned will be:
   // TrackInfo::kVideoTrack -> VideoInfo.
   // TrackInfo::kAudioTrack -> AudioInfo.
   // respectively.
   virtual UniquePtr<TrackInfo> GetInfo() const = 0;

--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -193,17 +193,17 @@ MediaDecoder::ResourceCallback::NotifyNe
 }
 
 void
 MediaDecoder::ResourceCallback::NotifyDecodeError()
 {
   RefPtr<ResourceCallback> self = this;
   nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction([=] () {
     if (self->mDecoder) {
-      self->mDecoder->DecodeError();
+      self->mDecoder->DecodeError(NS_ERROR_DOM_MEDIA_FATAL_ERR);
     }
   });
   AbstractThread::MainThread()->Dispatch(r.forget());
 }
 
 /* static */ void
 MediaDecoder::ResourceCallback::TimerCallback(nsITimer* aTimer, void* aClosure)
 {
@@ -602,16 +602,17 @@ MediaDecoder::Shutdown()
   // This changes the decoder state to SHUTDOWN and does other things
   // necessary to unblock the state machine thread if it's blocked, so
   // the asynchronous shutdown in nsDestroyStateMachine won't deadlock.
   if (mDecoderStateMachine) {
     mTimedMetadataListener.Disconnect();
     mMetadataLoadedListener.Disconnect();
     mFirstFrameLoadedListener.Disconnect();
     mOnPlaybackEvent.Disconnect();
+    mOnPlaybackErrorEvent.Disconnect();
     mOnMediaNotSeekable.Disconnect();
 
     mDecoderStateMachine->BeginShutdown()
       ->Then(AbstractThread::MainThread(), __func__, this,
              &MediaDecoder::FinishShutdown,
              &MediaDecoder::FinishShutdown);
   } else {
     // Ensure we always unregister asynchronously in order not to disrupt
@@ -656,32 +657,35 @@ MediaDecoder::OnPlaybackEvent(MediaEvent
       ComputePlaybackRate();
       break;
     case MediaEventType::PlaybackEnded:
       PlaybackEnded();
       break;
     case MediaEventType::SeekStarted:
       SeekingStarted();
       break;
-    case MediaEventType::DecodeError:
-      DecodeError();
-      break;
     case MediaEventType::Invalidate:
       Invalidate();
       break;
     case MediaEventType::EnterVideoSuspend:
       mOwner->DispatchAsyncEvent(NS_LITERAL_STRING("mozentervideosuspend"));
       break;
     case MediaEventType::ExitVideoSuspend:
       mOwner->DispatchAsyncEvent(NS_LITERAL_STRING("mozexitvideosuspend"));
       break;
   }
 }
 
 void
+MediaDecoder::OnPlaybackErrorEvent(const MediaResult& aError)
+{
+  DecodeError(aError);
+}
+
+void
 MediaDecoder::FinishShutdown()
 {
   MOZ_ASSERT(NS_IsMainThread());
   mDecoderStateMachine->BreakCycles();
   SetStateMachine(nullptr);
   mVideoFrameContainer = nullptr;
   MediaShutdownManager::Instance().Unregister(this);
 }
@@ -744,16 +748,18 @@ MediaDecoder::SetStateMachineParameters(
     AbstractThread::MainThread(), this, &MediaDecoder::OnMetadataUpdate);
   mMetadataLoadedListener = mDecoderStateMachine->MetadataLoadedEvent().Connect(
     AbstractThread::MainThread(), this, &MediaDecoder::MetadataLoaded);
   mFirstFrameLoadedListener = mDecoderStateMachine->FirstFrameLoadedEvent().Connect(
     AbstractThread::MainThread(), this, &MediaDecoder::FirstFrameLoaded);
 
   mOnPlaybackEvent = mDecoderStateMachine->OnPlaybackEvent().Connect(
     AbstractThread::MainThread(), this, &MediaDecoder::OnPlaybackEvent);
+  mOnPlaybackErrorEvent = mDecoderStateMachine->OnPlaybackErrorEvent().Connect(
+    AbstractThread::MainThread(), this, &MediaDecoder::OnPlaybackErrorEvent);
   mOnMediaNotSeekable = mDecoderStateMachine->OnMediaNotSeekable().Connect(
     AbstractThread::MainThread(), this, &MediaDecoder::OnMediaNotSeekable);
 }
 
 void
 MediaDecoder::SetMinimizePrerollUntilPlaybackStarts()
 {
   MOZ_ASSERT(NS_IsMainThread());
@@ -1001,21 +1007,21 @@ MediaDecoder::NetworkError()
 {
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(!IsShutdown());
   mOwner->NetworkError();
   MOZ_ASSERT(IsShutdown());
 }
 
 void
-MediaDecoder::DecodeError()
+MediaDecoder::DecodeError(const MediaResult& aError)
 {
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(!IsShutdown());
-  mOwner->DecodeError();
+  mOwner->DecodeError(aError);
   MOZ_ASSERT(IsShutdown());
 }
 
 void
 MediaDecoder::UpdateSameOriginStatus(bool aSameOrigin)
 {
   MOZ_ASSERT(NS_IsMainThread());
   mSameOriginMedia = aSameOrigin;