--- a/accessible/mac/mozAccessible.mm
+++ b/accessible/mac/mozAccessible.mm
@@ -1101,17 +1101,21 @@ struct RoleDescrComparator
 
   return [NSString stringWithFormat:@"(%p) %@", self, [self role]];
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
 }
 
 - (BOOL)isFocused
 {
-  return FocusMgr()->IsFocused([self getGeckoAccessible]);
+  if (AccessibleWrap* accWrap = [self getGeckoAccessible]) {
+    return FocusMgr()->IsFocused(accWrap);
+  }
+
+  return false; //XXX: proxy implementation is needed.
 }
 
 - (BOOL)canBeFocused
 {
   if (AccessibleWrap* accWrap = [self getGeckoAccessible])
       return accWrap->InteractiveState() & states::FOCUSABLE;
 
   if (ProxyAccessible* proxy = [self getProxyAccessible])

--- a/browser/base/content/test/general/browser.ini
+++ b/browser/base/content/test/general/browser.ini
@@ -27,16 +27,18 @@ support-files =
   bug792517.html
   bug792517.sjs
   bug839103.css
   clipboard_pastefile.html
   contextmenu_common.js
   ctxmenu-image.png
   discovery.html
   download_page.html
+  download_page_1.txt
+  download_page_2.txt
   dummy_page.html
   feed_tab.html
   file_generic_favicon.ico
   file_with_favicon.html
   file_mediaPlayback.html
   file_bug970276_popup1.html
   file_bug970276_popup2.html
   file_bug970276_favicon1.ico

--- a/browser/base/content/test/general/browser_bug575561.js
+++ b/browser/base/content/test/general/browser_bug575561.js
@@ -1,15 +1,20 @@
 requestLongerTimeout(2);
 
 const TEST_URL = "http://example.com/browser/browser/base/content/test/general/app_bug575561.html";
 
 add_task(async function() {
   SimpleTest.requestCompleteLog();
 
+  // allow top level data: URI navigations, otherwise clicking data: link fails
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
+
   // Pinned: Link to the same domain should not open a new tab
   // Tests link to http://example.com/browser/browser/base/content/test/general/dummy_page.html
   await testLink(0, true, false);
   // Pinned: Link to a different subdomain should open a new tab
   // Tests link to http://test1.example.com/browser/browser/base/content/test/general/dummy_page.html
   await testLink(1, true, true);
 
   // Pinned: Link to a different domain should open a new tab

--- a/browser/base/content/test/general/browser_bug734076.js
+++ b/browser/base/content/test/general/browser_bug734076.js
@@ -1,12 +1,19 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 add_task(async function() {
+
+  // allow top level data: URI navigations, otherwise loading data: URIs
+  // in toplevel windows fail.
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
+
   let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, null, false);
 
   let browser = tab.linkedBrowser;
   browser.stop(); // stop the about:blank load
 
   let writeDomainURL = encodeURI("data:text/html,<script>document.write(document.domain);</script>");
 
   let tests = [

--- a/browser/base/content/test/general/browser_fullscreen-window-open.js
+++ b/browser/base/content/test/general/browser_fullscreen-window-open.js
@@ -1,29 +1,31 @@
 /* eslint-disable mozilla/no-arbitrary-setTimeout */
 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 Components.utils.import("resource://gre/modules/Services.jsm");
 
 var Cc = Components.classes;
 var Ci = Components.interfaces;
 
 const PREF_DISABLE_OPEN_NEW_WINDOW = "browser.link.open_newwindow.disabled_in_fullscreen";
+const PREF_BLOCK_TOPLEVEL_DATA = "security.data_uri.block_toplevel_data_uri_navigations";
 const isOSX = (Services.appinfo.OS === "Darwin");
 
 const TEST_FILE = "file_fullscreen-window-open.html";
 const gHttpTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/",
                                                           "http://127.0.0.1:8888/");
 
 var newWin;
 var newBrowser;
 
 async function test() {
   waitForExplicitFinish();
 
   Services.prefs.setBoolPref(PREF_DISABLE_OPEN_NEW_WINDOW, true);
+  Services.prefs.setBoolPref(PREF_BLOCK_TOPLEVEL_DATA, false);
 
   newWin = await BrowserTestUtils.openNewBrowserWindow();
   newBrowser = newWin.gBrowser;
   await promiseTabLoadEvent(newBrowser.selectedTab, gHttpTestRoot + TEST_FILE);
 
   // Enter browser fullscreen mode.
   newWin.BrowserFullScreen();
 
@@ -32,16 +34,17 @@ async function test() {
 
 registerCleanupFunction(async function() {
   // Exit browser fullscreen mode.
   newWin.BrowserFullScreen();
 
   await BrowserTestUtils.closeWindow(newWin);
 
   Services.prefs.clearUserPref(PREF_DISABLE_OPEN_NEW_WINDOW);
+  Services.prefs.clearUserPref(PREF_BLOCK_TOPLEVEL_DATA);
 });
 
 var gTests = [
   test_open,
   test_open_with_size,
   test_open_with_pos,
   test_open_with_outerSize,
   test_open_with_innerSize,

--- a/browser/base/content/test/general/download_page.html
+++ b/browser/base/content/test/general/download_page.html
@@ -6,23 +6,23 @@ https://bugzilla.mozilla.org/show_bug.cg
   <head>
     <title>Test for the download attribute</title>
 
   </head>
   <body>
     <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=676619">Bug 676619</a>
     <br/>
     <ul>
-        <li><a href="data:text/plain,Hey What are you looking for?"
+        <li><a href="download_page_1.txt"
                 download="test.txt" id="link1">Download "test.txt"</a></li>
         <li><a href="video.ogg"
                 download id="link2">Download "video.ogg"</a></li>
         <li><a href="video.ogg"
                 download="just some video" id="link3">Download "just some video"</a></li>
-        <li><a href="data:text/plain,test"
+        <li><a href="download_page_2.txt"
                 download="with-target.txt" id="link4">Download "with-target.txt"</a></li>
         <li><a href="javascript:(1+2)+''"
             download="javascript.txt" id="link5">Download "javascript.txt"</a></li>
     </ul>
     <script>
         var li = document.createElement("li");
         var a = document.createElement("a");
 

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/general/download_page_1.txt
@@ -0,0 +1,1 @@
+Hey What are you looking for?

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/general/download_page_2.txt
@@ -0,0 +1,1 @@
+test

--- a/browser/base/content/test/popups/browser.ini
+++ b/browser/base/content/test/popups/browser.ini
@@ -1,6 +1,12 @@
 [browser_popupUI.js]
 [browser_popup_blocker.js]
-support-files = popup_blocker.html
+support-files =
+  popup_blocker.html
+  popup_blocker_a.html
+  popup_blocker_b.html
 skip-if = (os == 'linux') || (e10s && debug) # Frequent bug 1081925 and bug 1125520 failures
 [browser_popup_frames.js]
-support-files = popup_blocker.html
+support-files =
+  popup_blocker.html
+  popup_blocker_a.html
+  popup_blocker_b.html

--- a/browser/base/content/test/popups/browser_popup_blocker.js
+++ b/browser/base/content/test/popups/browser_popup_blocker.js
@@ -59,18 +59,18 @@ add_task(async function test_opening_blo
   let allow = menu.querySelector("[observes='blockedPopupAllowSite']");
   allow.doCommand();
   await BrowserTestUtils.waitForCondition(() =>
     popupTabs.length == 2 &&
     popupTabs.every(aTab => aTab.linkedBrowser.currentURI.spec != "about:blank"));
 
   gBrowser.tabContainer.removeEventListener("TabOpen", onTabOpen);
 
-  is(popupTabs[0].linkedBrowser.currentURI.spec, "data:text/plain;charset=utf-8,a", "Popup a");
-  is(popupTabs[1].linkedBrowser.currentURI.spec, "data:text/plain;charset=utf-8,b", "Popup b");
+  ok(popupTabs[0].linkedBrowser.currentURI.spec.endsWith("popup_blocker_a.html"), "Popup a");
+  ok(popupTabs[1].linkedBrowser.currentURI.spec.endsWith("popup_blocker_b.html"), "Popup b");
 
   // Clean up.
   gBrowser.removeTab(tab);
   for (let popup of popupTabs) {
     gBrowser.removeTab(popup);
   }
   clearAllPermissionsByPrefix("popup");
   // Ensure the menu closes.

--- a/browser/base/content/test/popups/popup_blocker.html
+++ b/browser/base/content/test/popups/popup_blocker.html
@@ -1,13 +1,13 @@
 <!doctype html>
 <html>
   <head>
     <meta charset="UTF-8">
     <title>Page creating two popups</title>
   </head>
   <body>
     <script type="text/javascript">
-      window.open("data:text/plain;charset=utf-8,a", "a");
-      window.open("data:text/plain;charset=utf-8,b", "b");
+      window.open("popup_blocker_a.html", "a");
+      window.open("popup_blocker_b.html", "b");
     </script>
   </body>
 </html>

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/popups/popup_blocker_a.html
@@ -0,0 +1,1 @@
+<html><body>a</body></html>

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/popups/popup_blocker_b.html
@@ -0,0 +1,1 @@
+<html><body>b</body></html>

--- a/browser/base/content/test/urlbar/browser.ini
+++ b/browser/base/content/test/urlbar/browser.ini
@@ -24,16 +24,17 @@ support-files =
 [browser_bug1024133-switchtab-override-keynav.js]
 [browser_bug1025195_switchToTabHavingURI_aOpenParams.js]
 [browser_bug1070778.js]
 [browser_bug1225194-remotetab.js]
 [browser_bug304198.js]
 [browser_bug556061.js]
 subsuite = clipboard
 [browser_bug562649.js]
+support-files = file_bug562649.html
 [browser_bug623155.js]
 support-files =
   redirect_bug623155.sjs
 [browser_bug783614.js]
 [browser_canonizeURL.js]
 [browser_dragdropURL.js]
 [browser_locationBarCommand.js]
 [browser_locationBarExternalLoad.js]
@@ -114,17 +115,16 @@ support-files =
   file_urlbar_edit_dos.html
 [browser_urlbar_searchsettings.js]
 [browser_urlbar_search_speculative_connect.js]
 [browser_urlbar_search_speculative_connect_engine.js]
 support-files =
   searchSuggestionEngine2.xml
   searchSuggestionEngine.sjs
 [browser_urlbar_search_speculative_connect_mousedown.js]
-[browser_urlbar_search_no_speculative_connect_with_client_cert.js]
 [browser_urlbar_stop_pending.js]
 support-files =
   slow-page.sjs
 [browser_urlbar_remoteness_switch.js]
 run-if = e10s
 [browser_urlHighlight.js]
 [browser_wyciwyg_urlbarCopying.js]
 subsuite = clipboard

--- a/browser/base/content/test/urlbar/browser_bug562649.js
+++ b/browser/base/content/test/urlbar/browser_bug562649.js
@@ -1,10 +1,11 @@
 function test() {
-  const URI = "data:text/plain,bug562649";
+  const TEST_PATH = getRootDirectory(gTestPath).replace("chrome://mochitests/content", "https://example.com");
+  const URI = TEST_PATH + "file_bug562649.html";
   window.browserDOMWindow.openURI(makeURI(URI),
                                   null,
                                   Ci.nsIBrowserDOMWindow.OPEN_NEWTAB,
                                   Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL,
                                   Services.scriptSecurityManager.getSystemPrincipal());
 
   is(gBrowser.userTypedValue, URI, "userTypedValue matches test URI");
   is(gURLBar.value, URI, "location bar value matches test URI");

deleted file mode 100644
--- a/browser/base/content/test/urlbar/browser_urlbar_search_no_speculative_connect_with_client_cert.js
+++ /dev/null
@@ -1,182 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-// Test that if we're attempting to speculatively connect to a site but it
-// requests a client certificate, we cancel the speculative connection (this
-// avoids an unexpected "select a client certificate" dialog).
-
-const { MockRegistrar } =
-  Cu.import("resource://testing-common/MockRegistrar.jsm", {});
-
-const certService = Cc["@mozilla.org/security/local-cert-service;1"]
-                      .getService(Ci.nsILocalCertService);
-const certOverrideService = Cc["@mozilla.org/security/certoverride;1"]
-                              .getService(Ci.nsICertOverrideService);
-
-const host = "localhost";
-let uri;
-let handshakeDone = false;
-let expectingChooseCertificate = false;
-let chooseCertificateCalled = false;
-
-const clientAuthDialogs = {
-  chooseCertificate(ctx, hostname, port, organization, issuerOrg, certList,
-                    selectedIndex) {
-    ok(expectingChooseCertificate,
-       `${expectingChooseCertificate ? "" : "not "}expecting chooseCertificate to be called`);
-    is(certList.length, 1, "should have only one client certificate available");
-    selectedIndex.value = 0;
-    chooseCertificateCalled = true;
-    return true;
-  },
-
-  QueryInterface: XPCOMUtils.generateQI([Ci.nsIClientAuthDialogs]),
-};
-
-function startServer(cert) {
-  let tlsServer = Cc["@mozilla.org/network/tls-server-socket;1"]
-                    .createInstance(Ci.nsITLSServerSocket);
-  tlsServer.init(-1, true, -1);
-  tlsServer.serverCert = cert;
-
-  let input, output;
-
-  let listener = {
-    onSocketAccepted(socket, transport) {
-      info("Accepted TLS client connection");
-      let connectionInfo = transport.securityInfo
-                           .QueryInterface(Ci.nsITLSServerConnectionInfo);
-      connectionInfo.setSecurityObserver(listener);
-      input = transport.openInputStream(0, 0, 0);
-      output = transport.openOutputStream(0, 0, 0);
-    },
-
-    onHandshakeDone(socket, status) {
-      info("TLS handshake done");
-      handshakeDone = true;
-
-      input.asyncWait({
-        onInputStreamReady(readyInput) {
-          try {
-            let request = NetUtil.readInputStreamToString(readyInput,
-                                                          readyInput.available());
-            ok(request.startsWith("GET /") && request.includes("HTTP/1.1"),
-               "expecting an HTTP/1.1 GET request");
-            let response = "HTTP/1.1 200 OK\r\nContent-Type:text/plain\r\n" +
-                           "Connection:Close\r\nContent-Length:2\r\n\r\nOK";
-            output.write(response, response.length);
-          } catch (e) {
-            // This will fail when we close the speculative connection.
-          }
-        }
-      }, 0, 0, Services.tm.currentThread);
-    },
-
-    onStopListening() {
-      info("onStopListening");
-      input.close();
-      output.close();
-    }
-  };
-
-  tlsServer.setSessionCache(false);
-  tlsServer.setSessionTickets(false);
-  tlsServer.setRequestClientCertificate(Ci.nsITLSServerSocket.REQUEST_ALWAYS);
-
-  tlsServer.asyncListen(listener);
-
-  return tlsServer;
-}
-
-let server;
-
-add_task(async function setup() {
-  await SpecialPowers.pushPrefEnv({
-    set: [["browser.urlbar.autoFill", true],
-          // Turn off search suggestion so we won't speculative connect to the search engine.
-          ["browser.search.suggest.enabled", false],
-          ["browser.urlbar.speculativeConnect.enabled", true],
-          // In mochitest this number is 0 by default but we have to turn it on.
-          ["network.http.speculative-parallel-limit", 6],
-          // The http server is using IPv4, so it's better to disable IPv6 to avoid weird
-          // networking problem.
-          ["network.dns.disableIPv6", true],
-          ["security.default_personal_cert", "Ask Every Time"]],
-  });
-
-  let clientAuthDialogsCID =
-    MockRegistrar.register("@mozilla.org/nsClientAuthDialogs;1",
-                           clientAuthDialogs);
-
-  let cert = await new Promise((resolve, reject) => {
-    certService.getOrCreateCert("speculative-connect", {
-      handleCert(c, rv) {
-        if (!Components.isSuccessCode(rv)) {
-          reject(rv);
-          return;
-        }
-        resolve(c);
-      }
-    });
-  });
-  server = startServer(cert);
-  uri = `https://${host}:${server.port}/`;
-  info(`running tls server at ${uri}`);
-  await PlacesTestUtils.addVisits([{
-    uri,
-    title: "test visit for speculative connection",
-    transition: Ci.nsINavHistoryService.TRANSITION_TYPED,
-  }]);
-
-  let overrideBits = Ci.nsICertOverrideService.ERROR_UNTRUSTED |
-                     Ci.nsICertOverrideService.ERROR_MISMATCH;
-  certOverrideService.rememberValidityOverride("localhost", server.port, cert,
-                                               overrideBits, true);
-
-  registerCleanupFunction(async function() {
-    await PlacesUtils.history.clear();
-    MockRegistrar.unregister(clientAuthDialogsCID);
-    certOverrideService.clearValidityOverride("localhost", server.port);
-  });
-});
-
-add_task(async function popup_mousedown_no_client_cert_dialog_until_navigate_test() {
-  const test = {
-    // To not trigger autofill, search keyword starts from the second character.
-    search: host.substr(1, 4),
-    completeValue: uri
-  };
-  info(`Searching for '${test.search}'`);
-  await promiseAutocompleteResultPopup(test.search, window, true);
-  let controller = gURLBar.popup.input.controller;
-  // The first item should be 'Search with ...' thus we want the second.
-  let value = controller.getFinalCompleteValueAt(1);
-  info(`The value of the second item is ${value}`);
-  is(value, test.completeValue, "The second item has the url we visited.");
-
-  await BrowserTestUtils.waitForCondition(() => {
-    return !!gURLBar.popup.richlistbox.childNodes[1] &&
-           is_visible(gURLBar.popup.richlistbox.childNodes[1]);
-  }, "the node is there.");
-
-  let listitem = gURLBar.popup.richlistbox.childNodes[1];
-  EventUtils.synthesizeMouse(listitem, 10, 10, {type: "mousedown"}, window);
-  is(gURLBar.popup.richlistbox.selectedIndex, 1, "The second item is selected");
-  // Since we don't know before connecting that a server will request a client
-  // certificate, we actually do make a speculative connection. The trick is
-  // that we cancel it and don't re-use it if we are asked for a certificate
-  // (and of course we don't show the certificate-picking UI). So, the TLS
-  // server will actually complete the handshake.
-  await BrowserTestUtils.waitForCondition(() => handshakeDone,
-                                          "waiting for handshake to complete");
-  // Now mouseup, expect that we choose a client certificate, and expect that we
-  // successfully load a page.
-  expectingChooseCertificate = true;
-  EventUtils.synthesizeMouse(listitem, 10, 10, {type: "mouseup"}, window);
-  await BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
-  ok(chooseCertificateCalled, "chooseCertificate must have been called");
-  server.close();
-});

new file mode 100644
--- /dev/null
+++ b/browser/base/content/test/urlbar/file_bug562649.html
@@ -0,0 +1,1 @@
+<html><body>bug562649</body></html>

--- a/browser/components/extensions/test/browser/browser_ext_tabs_executeScript_bad.js
+++ b/browser/components/extensions/test/browser/browser_ext_tabs_executeScript_bad.js
@@ -198,16 +198,22 @@ add_task(async function testBadPermissio
     },
   });
 
   await BrowserTestUtils.removeTab(tab2);
   await BrowserTestUtils.removeTab(tab1);
 });
 
 add_task(async function testMatchDataURI() {
+  // allow top level data: URI navigations, otherwise
+  // window.location.href = data: would be blocked
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]],
+  });
+
   const target = ExtensionTestUtils.loadExtension({
     files: {
       "page.html": `<!DOCTYPE html>
         <meta charset="utf-8">
         <script src="page.js"></script>
         <iframe id="inherited" src="data:text/html;charset=utf-8,inherited"></iframe>
       `,
       "page.js": function() {

--- a/browser/components/originattributes/test/browser/browser_firstPartyIsolation_aboutPages.js
+++ b/browser/components/originattributes/test/browser/browser_firstPartyIsolation_aboutPages.js
@@ -63,16 +63,21 @@ function frame_script() {
   let element = content.document.getElementById("test");
   element.click();
 }
 
 /**
  * Check if data: URI inherits firstPartyDomain from about:blank correctly.
  */
 add_task(async function test_remote_window_open_data_uri() {
+  // allow top level data: URI navigations, otherwise
+  // <a href="data:" would fail.
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
   let win = await BrowserTestUtils.openNewBrowserWindow({ remote: true });
   let browser = win.gBrowser.selectedBrowser;
   let mm = browser.messageManager;
   mm.loadFrameScript("data:,(" + frame_script.toString() + ")();", true);
 
   await BrowserTestUtils.browserLoaded(browser, false, function(url) {
     return url == "data:text/plain,hello";
   });

--- a/browser/components/places/content/controller.js
+++ b/browser/components/places/content/controller.js
@@ -1593,29 +1593,36 @@ var PlacesControllerDragHelper = {
     let parentGuid = insertionPoint.guid;
     let tagName = insertionPoint.tagName;
 
     // Following flavors may contain duplicated data.
     let duplicable = new Map();
     duplicable.set(PlacesUtils.TYPE_UNICODE, new Set());
     duplicable.set(PlacesUtils.TYPE_X_MOZ_URL, new Set());
 
+    // Collect all data from the DataTransfer before processing it, as the
+    // DataTransfer is only valid during the synchronous handling of the `drop`
+    // event handler callback.
+    let dtItems = [];
     for (let i = 0; i < dropCount; ++i) {
       let flavor = this.getFirstValidFlavor(dt.mozTypesAt(i));
       if (!flavor)
         return;
 
       let data = dt.mozGetDataAt(flavor, i);
       if (duplicable.has(flavor)) {
         let handled = duplicable.get(flavor);
         if (handled.has(data))
           continue;
         handled.add(data);
       }
+      dtItems.push({flavor, data});
+    }
 
+    for (let {flavor, data} of dtItems) {
       let nodes;
       if (flavor != TAB_DROP_TYPE) {
         nodes = PlacesUtils.unwrapNodes(data, flavor);
       } else if (data instanceof XULElement && data.localName == "tab" &&
                data.ownerGlobal instanceof ChromeWindow) {
         let uri = data.linkedBrowser.currentURI;
         let spec = uri ? uri.spec : "about:blank";
         nodes = [{ uri: spec,

--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_newtab_from_popup.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_newtab_from_popup.js
@@ -17,16 +17,20 @@ const POPUP_LINK = `data:text/html;chars
 const WINDOW_BODY = `data:text/html,
                      <a href="%23" id="first"
                         onclick="window.open('${POPUP_LINK}', '_blank',
                                              'width=630,height=500')">
                        First click this.
                      </a>`;
 
 add_task(async function test_private_popup_window_opens_private_tabs() {
+  // allow top level data: URI navigations, otherwise clicking a data: link fails
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
   let privWin = await BrowserTestUtils.openNewBrowserWindow({ private: true });
 
   // Sanity check - this browser better be private.
   ok(PrivateBrowsingUtils.isWindowPrivate(privWin),
      "Opened a private browsing window.");
 
   // First, open a private browsing window, and load our
   // testing page.

--- a/browser/components/sessionstore/content/content-sessionStore.js
+++ b/browser/components/sessionstore/content/content-sessionStore.js
@@ -46,16 +46,18 @@ var gCurrentEpoch = 0;
 
 // A bound to the size of data to store for DOM Storage.
 const DOM_STORAGE_LIMIT_PREF = "browser.sessionstore.dom_storage_limit";
 
 // This pref controls whether or not we send updates to the parent on a timeout
 // or not, and should only be used for tests or debugging.
 const TIMEOUT_DISABLED_PREF = "browser.sessionstore.debug.no_auto_updates";
 
+const PREF_INTERVAL = "browser.sessionstore.interval";
+
 const kNoIndex = Number.MAX_SAFE_INTEGER;
 const kLastIndex = Number.MAX_SAFE_INTEGER - 1;
 
 /**
  * A function that will recursively call |cb| to collected data for all
  * non-dynamic frames in the current frame/docShell tree.
  */
 function mapFrameTree(callback) {
@@ -728,29 +730,46 @@ var MessageQueue = {
 
   /**
    * The delay (in ms) used to delay sending changes after data has been
    * invalidated.
    */
   BATCH_DELAY_MS: 1000,
 
   /**
+   * The minimum idle period (in ms) we need for sending data to chrome process.
+   */
+  NEEDED_IDLE_PERIOD_MS: 5,
+
+  /**
+   * Timeout for waiting an idle period to send data. We will set this from
+   * the pref "browser.sessionstore.interval".
+   */
+  _timeoutWaitIdlePeriodMs: null,
+
+  /**
    * The current timeout ID, null if there is no queue data. We use timeouts
    * to damp a flood of data changes and send lots of changes as one batch.
    */
   _timeout: null,
 
   /**
    * Whether or not sending batched messages on a timer is disabled. This should
    * only be used for debugging or testing. If you need to access this value,
    * you should probably use the timeoutDisabled getter.
    */
   _timeoutDisabled: false,
 
   /**
+   * The idle callback ID referencing an active idle callback. When no idle
+   * callback is pending, this is null.
+   * */
+  _idleCallbackID: null,
+
+  /**
    * True if batched messages are not being fired on a timer. This should only
    * ever be true when debugging or during tests.
    */
   get timeoutDisabled() {
     return this._timeoutDisabled;
   },
 
   /**
@@ -766,28 +785,58 @@ var MessageQueue = {
     }
 
     return val;
   },
 
   init() {
     this.timeoutDisabled =
       Services.prefs.getBoolPref(TIMEOUT_DISABLED_PREF);
+    this._timeoutWaitIdlePeriodMs =
+      Services.prefs.getIntPref(PREF_INTERVAL);
 
     Services.prefs.addObserver(TIMEOUT_DISABLED_PREF, this);
+    Services.prefs.addObserver(PREF_INTERVAL, this);
   },
 
   uninit() {
     Services.prefs.removeObserver(TIMEOUT_DISABLED_PREF, this);
+    Services.prefs.removeObserver(PREF_INTERVAL, this);
+    this.cleanupTimers();
+  },
+
+  /**
+   * Cleanup pending idle callback and timer.
+   */
+  cleanupTimers() {
+    if (this._idleCallbackID) {
+      content.cancelIdleCallback(this._idleCallbackID);
+      this._idleCallbackID = null;
+    }
+    if (this._timeout) {
+      clearTimeout(this._timeout);
+      this._timeout = null;
+    }
   },
 
   observe(subject, topic, data) {
-    if (topic == "nsPref:changed" && data == TIMEOUT_DISABLED_PREF) {
-      this.timeoutDisabled =
-        Services.prefs.getBoolPref(TIMEOUT_DISABLED_PREF);
+    if (topic == "nsPref:changed") {
+      switch (data) {
+        case TIMEOUT_DISABLED_PREF:
+          this.timeoutDisabled =
+            Services.prefs.getBoolPref(TIMEOUT_DISABLED_PREF);
+          break;
+        case PREF_INTERVAL:
+          this._timeoutWaitIdlePeriodMs =
+            Services.prefs.getIntPref(PREF_INTERVAL);
+          break;
+        default:
+          debug("received unknown message '" + data + "'");
+          break;
+      }
     }
   },
 
   /**
    * Pushes a given |value| onto the queue. The given |key| represents the type
    * of data that is stored and can override data that has been queued before
    * but has not been sent to the parent process, yet.
    *
@@ -798,39 +847,58 @@ var MessageQueue = {
    *        process.
    */
   push(key, fn) {
     this._data.set(key, fn);
 
     if (!this._timeout && !this._timeoutDisabled) {
       // Wait a little before sending the message to batch multiple changes.
       this._timeout = setTimeoutWithTarget(
-        () => this.send(), this.BATCH_DELAY_MS, tabEventTarget);
+        () => this.sendWhenIdle(), this.BATCH_DELAY_MS, tabEventTarget);
     }
   },
 
   /**
+   * Sends queued data when the remaining idle time is enough or waiting too
+   * long; otherwise, request an idle time again. If the |deadline| is not
+   * given, this function is going to schedule the first request.
+   *
+   * @param deadline (object)
+   *        An IdleDeadline object passed by requestIdleCallback().
+   */
+  sendWhenIdle(deadline) {
+    if (deadline) {
+      if (deadline.didTimeout || deadline.timeRemaining() > MessageQueue.NEEDED_IDLE_PERIOD_MS) {
+        MessageQueue.send();
+        return;
+      }
+    } else if (MessageQueue._idleCallbackID) {
+      // Bail out if there's a pending run.
+      return;
+    }
+    MessageQueue._idleCallbackID =
+      content.requestIdleCallback(MessageQueue.sendWhenIdle, {timeout: MessageQueue._timeoutWaitIdlePeriodMs});
+   },
+
+  /**
    * Sends queued data to the chrome process.
    *
    * @param options (object)
    *        {flushID: 123} to specify that this is a flush
    *        {isFinal: true} to signal this is the final message sent on unload
    */
   send(options = {}) {
     // Looks like we have been called off a timeout after the tab has been
     // closed. The docShell is gone now and we can just return here as there
     // is nothing to do.
     if (!docShell) {
       return;
     }
 
-    if (this._timeout) {
-      clearTimeout(this._timeout);
-      this._timeout = null;
-    }
+    this.cleanupTimers();
 
     let flushID = (options && options.flushID) || 0;
     let histID = "FX_SESSION_RESTORE_CONTENT_COLLECT_DATA_MS";
 
     let data = {};
     for (let [key, func] of this._data) {
       if (key != "isPrivate") {
         TelemetryStopwatch.startKeyed(histID, key);

--- a/browser/components/sessionstore/test/browser.ini
+++ b/browser/components/sessionstore/test/browser.ini
@@ -65,17 +65,19 @@ support-files =
 
 #disabled-for-intermittent-failures--bug-766044, browser_459906_empty.html
 #disabled-for-intermittent-failures--bug-766044, browser_459906_sample.html
 #disabled-for-intermittent-failures--bug-765389, browser_461743_sample.html
 
 [browser_aboutPrivateBrowsing.js]
 [browser_aboutSessionRestore.js]
 [browser_async_duplicate_tab.js]
+support-files = file_async_duplicate_tab.html
 [browser_async_flushes.js]
+support-files = file_async_flushes.html
 run-if = e10s && crashreporter
 skip-if = debug # bug 1167933
 [browser_async_remove_tab.js]
 run-if = e10s
 skip-if = debug # bug 1211084
 [browser_attributes.js]
 [browser_backup_recovery.js]
 [browser_broadcast.js]
@@ -106,16 +108,18 @@ skip-if = (os == 'win') # bug 1331853
 [browser_purge_shistory.js]
 skip-if = e10s # Bug 1271024
 [browser_replace_load.js]
 [browser_restore_redirect.js]
 [browser_restore_cookies_noOriginAttributes.js]
 [browser_scrollPositions.js]
 [browser_scrollPositionsReaderMode.js]
 [browser_sessionHistory.js]
+support-files =
+  file_sessionHistory_hashchange.html
 [browser_sessionStorage.js]
 [browser_sessionStorage_size.js]
 [browser_tab_label_during_restore.js]
 [browser_swapDocShells.js]
 [browser_switch_remoteness.js]
 run-if = e10s
 [browser_upgrade_backup.js]
 [browser_windowRestore_perwindowpb.js]

--- a/browser/components/sessionstore/test/browser_911547.js
+++ b/browser/components/sessionstore/test/browser_911547.js
@@ -6,16 +6,20 @@
 //    this tests that session restore component does restore the right
 //    content security policy with the document. (The policy being
 //    tested disallows inline scripts).
 // b) if security.data_uri.unique_opaque_origin == true, then
 //    this tests that data: URIs do not inherit the CSP from
 //    it's enclosing context.
 
 add_task(async function test() {
+  // allow top level data: URI navigations, otherwise clicking a data: link fails
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
   let dataURIPref = Services.prefs.getBoolPref("security.data_uri.unique_opaque_origin");
   // create a tab that has a CSP
   let testURL = "http://mochi.test:8888/browser/browser/components/sessionstore/test/browser_911547_sample.html";
   let tab = gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser, testURL);
   gBrowser.selectedTab = tab;
 
   let browser = tab.linkedBrowser;
   await promiseBrowserLoaded(browser);

--- a/browser/components/sessionstore/test/browser_async_duplicate_tab.js
+++ b/browser/components/sessionstore/test/browser_async_duplicate_tab.js
@@ -1,11 +1,13 @@
 "use strict";
 
-const URL = "data:text/html;charset=utf-8,<a href=%23>clickme</a>";
+const PATH = getRootDirectory(gTestPath)
+             .replace("chrome://mochitests/content/", "http://example.com/");
+const URL = PATH + "file_async_duplicate_tab.html";
 
 add_task(async function test_duplicate() {
   // Create new tab.
   let tab = BrowserTestUtils.addTab(gBrowser, URL);
   let browser = tab.linkedBrowser;
   await promiseBrowserLoaded(browser);
 
   // Flush to empty any queued update messages.

--- a/browser/components/sessionstore/test/browser_async_flushes.js
+++ b/browser/components/sessionstore/test/browser_async_flushes.js
@@ -1,11 +1,13 @@
 "use strict";
 
-const URL = "data:text/html;charset=utf-8,<a href=%23>clickme</a>";
+const PATH = getRootDirectory(gTestPath)
+             .replace("chrome://mochitests/content/", "http://example.com/");
+const URL = PATH + "file_async_flushes.html";
 
 add_task(async function test_flush() {
   // Create new tab.
   let tab = BrowserTestUtils.addTab(gBrowser, URL);
   let browser = tab.linkedBrowser;
   await promiseBrowserLoaded(browser);
 
   // Flush to empty any queued update messages.

--- a/browser/components/sessionstore/test/browser_dynamic_frames.js
+++ b/browser/components/sessionstore/test/browser_dynamic_frames.js
@@ -3,16 +3,20 @@
 
 "use strict";
 
 /**
  * Ensure that static frames of framesets are serialized but dynamically
  * inserted iframes are ignored.
  */
 add_task(async function() {
+  // allow top level data: URI navigations, otherwise clicking a data: link fails
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
   // This URL has the following frames:
   //  + data:text/html,A (static)
   //  + data:text/html,B (static)
   //  + data:text/html,C (dynamic iframe)
   const URL = "data:text/html;charset=utf-8," +
               "<frameset cols=50%25,50%25><frame src='data:text/html,A'>" +
               "<frame src='data:text/html,B'></frameset>" +
               "<script>var i=document.createElement('iframe');" +
@@ -41,16 +45,20 @@ add_task(async function() {
 });
 
 /**
  * Ensure that iframes created by the network parser are serialized but
  * dynamically inserted iframes are ignored. Navigating a subframe should
  * create a second root entry that doesn't contain any dynamic children either.
  */
 add_task(async function() {
+  // allow top level data: URI navigations, otherwise clicking a data: link fails
+  await SpecialPowers.pushPrefEnv({
+    "set": [["security.data_uri.block_toplevel_data_uri_navigations", false]]
+  });
   // This URL has the following frames:
   //  + data:text/html,A (static)
   //  + data:text/html,C (dynamic iframe)
   const URL = "data:text/html;charset=utf-8," +
               "<iframe name=t src='data:text/html,A'></iframe>" +
               "<a id=lnk href='data:text/html,B' target=t>clickme</a>" +
               "<script>var i=document.createElement('iframe');" +
               "i.setAttribute('src', 'data:text/html,C');" +

--- a/browser/components/sessionstore/test/browser_sessionHistory.js
+++ b/browser/components/sessionstore/test/browser_sessionHistory.js
@@ -32,18 +32,19 @@ add_task(async function test_load_start(
   // Cleanup.
   gBrowser.removeTab(tab);
 });
 
 /**
  * Ensure that anchor navigation invalidates shistory.
  */
 add_task(async function test_hashchange() {
-  const URL = "data:text/html;charset=utf-8,<a id=a href=%23>clickme</a>";
-
+  const PATH = getRootDirectory(gTestPath)
+              .replace("chrome://mochitests/content/", "http://example.com/");
+  const URL = PATH + "file_sessionHistory_hashchange.html";
   // Create a new tab.
   let tab = BrowserTestUtils.addTab(gBrowser, URL);
   let browser = tab.linkedBrowser;
   await promiseBrowserLoaded(browser);
 
   // Check that we start with a single shistory entry.
   await TabStateFlusher.flush(browser);
   let {entries} = JSON.parse(ss.getTabState(tab));

new file mode 100644
--- /dev/null
+++ b/browser/components/sessionstore/test/file_async_duplicate_tab.html
@@ -0,0 +1,1 @@
+<a href=#>clickme</a>

new file mode 100644
--- /dev/null
+++ b/browser/components/sessionstore/test/file_async_flushes.html
@@ -0,0 +1,1 @@
+<a href=#>clickme</a>

new file mode 100644
--- /dev/null
+++ b/browser/components/sessionstore/test/file_sessionHistory_hashchange.html
@@ -0,0 +1,1 @@
+<a id=a href=#>clickme</a>

--- a/browser/installer/windows/nsis/stub.nsi
+++ b/browser/installer/windows/nsis/stub.nsi
@@ -743,22 +743,22 @@ Function createInstall
   FindWindow $7 "#32770" "" $HWNDPARENT
   ${GetDlgItemWidthHeight} $HWNDPARENT $8 $9
 
   ; Resize the Dialog to fill the entire window
   System::Call 'user32::MoveWindow(i$Dialog,i0,i0,i $8,i $9,i0)'
 
   ; The header string may need more than half the width of the window, but it's
   ; currently not close to needing multiple lines in any localization.
-  ${NSD_CreateLabelCenter} 0% ${NOW_INSTALLING_TOP_DU} 100% 47u "$(STUB_INSTALLING_LABEL)"
+  ${NSD_CreateLabelCenter} 0% ${NOW_INSTALLING_TOP_DU} 100% 47u "$(STUB_INSTALLING_LABEL2)"
   Pop $0
   SendMessage $0 ${WM_SETFONT} $FontInstalling 0
   SetCtlColors $0 ${INSTALL_BLURB_TEXT_COLOR} transparent
 
-  ${NSD_CreateLabelCenter} 0% ${INSTALL_BLURB_TOP_DU} 100% 60u "$(STUB_BLURB1)"
+  ${NSD_CreateLabelCenter} 0% ${INSTALL_BLURB_TOP_DU} 100% 60u "$(STUB_BLURB_FIRST1)"
   Pop $LabelBlurb
   SendMessage $LabelBlurb ${WM_SETFONT} $FontBlurb 0
   SetCtlColors $LabelBlurb ${INSTALL_BLURB_TEXT_COLOR} transparent
 
   StrCpy $CurrentBlurbIdx "0"
 
   ${GetTextWidthHeight} "$(STUB_BLURB_FOOTER2)" $FontFooter \
     ${INSTALL_FOOTER_WIDTH_DU} $R1 $R2
@@ -891,21 +891,21 @@ FunctionEnd
 
 Function NextBlurb
   ${NSD_KillTimer} NextBlurb
 
   IntOp $CurrentBlurbIdx $CurrentBlurbIdx + 1
   IntOp $CurrentBlurbIdx $CurrentBlurbIdx % 3
 
   ${If} $CurrentBlurbIdx == "0"
-    StrCpy $0 "$(STUB_BLURB1)"
+    StrCpy $0 "$(STUB_BLURB_FIRST1)"
   ${ElseIf} $CurrentBlurbIdx == "1"
-    StrCpy $0 "$(STUB_BLURB2)"
+    StrCpy $0 "$(STUB_BLURB_SECOND1)"
   ${ElseIf} $CurrentBlurbIdx == "2"
-    StrCpy $0 "$(STUB_BLURB3)"
+    StrCpy $0 "$(STUB_BLURB_THIRD1)"
   ${EndIf}
 
   SendMessage $LabelBlurb ${WM_SETTEXT} 0 "STR:$0"
 
   ${NSD_CreateTimer} ClearBlurb ${BlurbDisplayMS}
 FunctionEnd
 
 Function ClearBlurb

--- a/browser/locales/en-US/installer/nsisstrings.properties
+++ b/browser/locales/en-US/installer/nsisstrings.properties
@@ -23,21 +23,17 @@ INSTALLER_WIN_CAPTION=$BrandShortName In
 # The \n in the next two strings can be moved or deleted as needed to make
 # the string fit in the 3 lines of space available.
 STUB_CLEANUP_PAVEOVER_HEADER=$BrandShortName is already installed.\nLet's update it.
 STUB_CLEANUP_REINSTALL_HEADER=$BrandShortName has been installed before.\nLet's get you a new copy.
 STUB_CLEANUP_PAVEOVER_BUTTON=&Update
 STUB_CLEANUP_REINSTALL_BUTTON=Re-&install
 STUB_CLEANUP_CHECKBOX_LABEL=&Restore default settings and remove old add-ons for optimal performance
 
-STUB_INSTALLING_LABEL=Now installing
 STUB_INSTALLING_LABEL2=Now installing…
-STUB_BLURB1=Fast, responsive online experiences
-STUB_BLURB2=Compatibility with more of your favorite sites
-STUB_BLURB3=Built-in privacy tools for safer browsing
 STUB_BLURB_FIRST1=The fastest, most responsive $BrandShortName yet
 STUB_BLURB_SECOND1=Faster page loading and tab switching
 STUB_BLURB_THIRD1=Powerful private browsing
 STUB_BLURB_FOOTER2=Built for people, not for profit
 
 WARN_MIN_SUPPORTED_OSVER_MSG=Sorry, $BrandShortName can't be installed. This version of $BrandShortName requires ${MinSupportedVer} or newer. Please click the OK button for additional information.
 WARN_MIN_SUPPORTED_CPU_MSG=Sorry, $BrandShortName can't be installed. This version of $BrandShortName requires a processor with ${MinSupportedCPU} support. Please click the OK button for additional information.
 WARN_MIN_SUPPORTED_OSVER_CPU_MSG=Sorry, $BrandShortName can't be installed. This version of $BrandShortName requires ${MinSupportedVer} or newer and a processor with ${MinSupportedCPU} support. Please click the OK button for additional information.

--- a/build/moz.configure/windows.configure
+++ b/build/moz.configure/windows.configure
@@ -217,16 +217,21 @@ def valid_ucrt_sdk_dir(windows_sdk_dir, 
                 'CRT.' % windows_sdk_dir_env)
 
     valid_sdks = sorted(sdks, key=lambda x: sdks[x][0], reverse=True)
     if not valid_sdks:
         raise FatalCheckError('Cannot find the Universal CRT SDK. '
                               'Please install it.')
 
     version, sdk = sdks[valid_sdks[0]]
+    minimum_ucrt_version = Version('10.0.10586.0')
+    if version < minimum_ucrt_version:
+        raise FatalCheckError('Latest Universal CRT SDK version found %s'
+                              ' and minimum required is %s.'
+                              % (version,  minimum_ucrt_version))
 
     return namespace(
         path=sdk.path,
         include=sdk.include,
         lib=sdk.lib,
         version=version,
     )
 

--- a/devtools/client/framework/options-panel.css
+++ b/devtools/client/framework/options-panel.css
@@ -113,11 +113,11 @@
 #screenshot-options legend::after {
   content: "";
   display: inline-block;
   background-image: url("chrome://devtools/skin/images/command-screenshot.svg");
   width: 16px;
   height: 16px;
   vertical-align: sub;
   margin-inline-start: 5px;
-  filter: var(--icon-filter);
+  filter: var(--theme-icon-filter);
   opacity: 0.6;
 }

--- a/devtools/client/inspector/layout/components/Accordion.css
+++ b/devtools/client/inspector/layout/components/Accordion.css
@@ -34,17 +34,17 @@
   width: 100%;
   align-items: center;
   display: flex;
 
   -moz-user-select: none;
 }
 
 .accordion ._header:hover {
-  background-color: var(--theme-toolbar-background-hover);
+  background-color: var(--theme-toolbar-hover);
 }
 
 .accordion ._header:hover svg {
   fill: var(--theme-comment-alt);
 }
 
 .accordion ._content {
   border-bottom: 1px solid var(--theme-splitter-color);

--- a/devtools/client/netmonitor/src/assets/styles/netmonitor.css
+++ b/devtools/client/netmonitor/src/assets/styles/netmonitor.css
@@ -1177,17 +1177,17 @@ body,
   padding-inline-end: 0;
   margin-top: 3px;
   margin-bottom: 3px;
   margin-inline-end: 1em;
 }
 
 .requests-list-network-summary-button > .summary-info-icon {
   background: url(chrome://devtools/skin/images/profiler-stopwatch.svg) no-repeat;
-  filter: var(--icon-filter);
+  filter: var(--theme-icon-filter);
   width: 16px;
   height: 16px;
   opacity: 0.8;
 }
 
 .requests-list-network-summary-button:hover > .summary-info-icon {
   opacity: 1;
 }

--- a/devtools/client/responsive.html/index.css
+++ b/devtools/client/responsive.html/index.css
@@ -71,17 +71,17 @@ body,
 
 .toolbar-button:empty:hover:not(:disabled),
 .toolbar-button:empty:-moz-any(:hover:active, .checked):not(:disabled) {
   /* Reset background from .devtools-button */
   background: none;
 }
 
 .toolbar-button:active::before {
-  filter: var(--checked-icon-filter);
+  filter: var(--theme-icon-checked-filter);
 }
 
 select {
   -moz-appearance: none;
   background-color: var(--theme-toolbar-background);
   background-image: var(--viewport-selection-arrow);
   -moz-context-properties: fill;
   fill: currentColor;
@@ -161,17 +161,17 @@ select > option.divider {
   background-image: url("./images/screenshot.svg");
 }
 
 #global-exit-button::before {
   background-image: url("chrome://devtools/skin/images/close.svg");
 }
 
 #global-screenshot-button:disabled {
-  filter: var(--checked-icon-filter);
+  filter: var(--theme-icon-checked-filter);
   opacity: 1 !important;
 }
 
 #global-network-throttling-selector {
   height: 15px;
   padding-left: 0;
   width: 103px;
 }

--- a/devtools/client/shared/components/tabs/tabs.css
+++ b/devtools/client/shared/components/tabs/tabs.css
@@ -79,16 +79,21 @@
 
 .theme-dark .tabs .tabs-menu-item,
 .theme-light .tabs .tabs-menu-item {
   margin: 0;
   padding: 0;
   color: var(--theme-toolbar-color);
 }
 
+.theme-dark .tabs .tabs-menu-item.is-active,
+.theme-light .tabs .tabs-menu-item.is-active {
+  color: var(--theme-toolbar-selected-color);
+}
+
 .theme-dark .tabs .tabs-menu-item:last-child,
 .theme-light:not(.theme-firebug) .tabs .tabs-menu-item:last-child {
   border-inline-end-width: 1px;
 }
 
 .theme-dark .tabs .tabs-menu-item a,
 .theme-light .tabs .tabs-menu-item a {
   padding: 3px 15px;

--- a/devtools/client/shared/test/browser_theme.js
+++ b/devtools/client/shared/test/browser_theme.js
@@ -96,12 +96,12 @@ function testColorExistence() {
     "comment", "body-color", "body-color-alt", "content-color1", "content-color2",
     "content-color3", "highlight-green", "highlight-blue", "highlight-bluegrey",
     "highlight-purple", "highlight-lightorange", "highlight-orange", "highlight-red",
     "highlight-pink"
   ];
 
   for (let type of vars) {
     ok(getColor(type, "light"), `${type} is a valid color in light theme`);
-    ok(getColor(type, "dark"), `${type} is a valid color in light theme`);
-    ok(getColor(type, "firebug"), `${type} is a valid color in light theme`);
+    ok(getColor(type, "dark"), `${type} is a valid color in dark theme`);
+    ok(getColor(type, "firebug"), `${type} is a valid color in firebug theme`);
   }
 }

--- a/devtools/client/shared/widgets/filter-widget.css
+++ b/devtools/client/shared/widgets/filter-widget.css
@@ -226,14 +226,14 @@
 
 #toggle-presets {
   background: url(chrome://devtools/skin/images/pseudo-class.svg);
 }
 
 #filter-container .add,
 #filter-container .remove-button,
 #toggle-presets {
-  filter: var(--icon-filter);
+  filter: var(--theme-icon-filter);
 }
 
 .show-presets #toggle-presets {
   filter: url(chrome://devtools/skin/images/filters.svg#checked-icon-state);
 }

--- a/devtools/client/sourceeditor/editor.js
+++ b/devtools/client/sourceeditor/editor.js
@@ -546,17 +546,17 @@ Editor.prototype = {
 
   /**
    * Replaces whatever is in the text area with the contents of
    * the 'value' argument.
    */
   setText: function (value) {
     let cm = editors.get(this);
 
-    if (typeof value !== "string") {  // wasm?
+    if (typeof value !== "string" && "binary" in value) {  // wasm?
       // binary does not survive as Uint8Array, converting from string
       let binary = value.binary;
       let data = new Uint8Array(binary.length);
       for (let i = 0; i < data.length; i++) {
         data[i] = binary.charCodeAt(i);
       }
       let { lines, done } = getWasmText(this.getDoc(), data);
       const MAX_LINES = 10000000;

--- a/devtools/client/themes/common.css
+++ b/devtools/client/themes/common.css
@@ -289,38 +289,33 @@ checkbox:-moz-focusring {
 }
 
 /* Icon button styles */
 .devtools-toolbarbutton:not([label]) > .toolbarbutton-text {
   display: none;
 }
 
 /* Icon-only buttons */
-.devtools-button:empty::before,
-.devtools-toolbarbutton:not([label]):not([disabled]) > image {
-  opacity: 0.8;
-}
-
 .devtools-button:hover:empty:not(:disabled):before,
 .devtools-button.checked:empty::before,
 .devtools-toolbarbutton:not([label]):not([disabled=true]):hover > image,
 .devtools-toolbarbutton:not([label])[checked=true] > image,
 .devtools-toolbarbutton:not([label])[open=true] > image {
   opacity: 1;
 }
 
 .devtools-button:disabled,
 .devtools-toolbarbutton[disabled] {
   opacity: 0.5 !important;
 }
 
 .devtools-button.checked::before,
 .devtools-toolbarbutton:not([label])[checked=true] > image,
 .devtools-toolbarbutton:not([label])[open=true] > image {
-  filter: var(--checked-icon-filter);
+  filter: var(--theme-icon-checked-filter);
 }
 
 /* Button states */
 .devtools-toolbarbutton[label]:not([type=menu-button]),
 .devtools-toolbarbutton[standalone],
 .devtools-button[data-standalone],
 .devtools-button:not(:empty) {
   background: var(--toolbarbutton-background);

--- a/devtools/client/themes/images/filters.svg
+++ b/devtools/client/themes/images/filters.svg
@@ -1,25 +1,59 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <svg height="0" xmlns="http://www.w3.org/2000/svg">
-  <filter id="checked-icon-state">
+  <!-- DevTools icon filter: Grey 90 + 0.8 opacity (light theme normal) -->
+  <filter id="icon-normal-light">
     <feColorMatrix in="SourceGraphic" type="matrix"
-      values="0 0 0 0 0.043
-              0 0 0 0 0.415
-              0 0 0 0 0.79
+      values="0 0 0 0 0.01
+              0 0 0 0 0.01
+              0 0 0 0 0.01
+              0 0 0 0.8 0"/>
+  </filter>
+  <!-- DevTools icon filter: Photon Blue 60 (light theme selected) -->
+  <filter id="icon-selected-light">
+    <feColorMatrix in="SourceGraphic" type="matrix"
+      values="0 0 0 0 0
+              0 0 0 0 0.122
+              0 0 0 0 0.74
               0 0 0 1 0"/>
   </filter>
-  <filter id="dark-theme-checked-icon-state">
+  <!-- DevTools icon filter: Photon Blue 60 (light theme checked) -->
+  <filter id="icon-checked-light">
     <feColorMatrix in="SourceGraphic" type="matrix"
       values="0 0 0 0 0
+              0 0 0 0 0.122
+              0 0 0 0 0.74
+              0 0 0 1 0"/>
+  </filter>
+  <!-- DevTools icon filter: Grey 10 + 0.8 opacity (dark theme normal) -->
+  <filter id="icon-normal-dark">
+    <feColorMatrix in="SourceGraphic" type="matrix"
+      values="0 0 0 0 0.945
+              0 0 0 0 0.945
+              0 0 0 0 0.95
+              0 0 0 0.8 0"/>
+  </filter>
+  <!-- DevTools icon filter: white (dark theme selected) -->
+  <filter id="icon-selected-dark">
+    <feColorMatrix in="SourceGraphic" type="matrix"
+      values="0 0 0 0 1
               0 0 0 0 1
-              0 0 0 0 0.212
+              0 0 0 0 1
+              0 0 0 1 0"/>
+  </filter>
+  <!-- DevTools icon filter: syntax blue #75BFFF (dark theme checked) -->
+  <filter id="icon-checked-dark">
+    <feColorMatrix in="SourceGraphic" type="matrix"
+      values="0 0 0 0.18 0
+              0 0 0 0.52 0
+              0 0 0 1 0
               0 0 0 1 0"/>
   </filter>
 
   <!-- Web Audio Gradients -->
   <linearGradient id="bypass-light" x1="8%" y1="10%" x2="16%" y2="16%" spreadMethod="repeat">
     <stop offset="0%" stop-color="#dde1e4a0"/> <!-- theme-splitter-color (0.5 opacity) -->
     <stop offset="50%" stop-color="transparent"/>
   </linearGradient>

--- a/devtools/client/themes/shadereditor.css
+++ b/devtools/client/themes/shadereditor.css
@@ -52,17 +52,17 @@
 }
 
 .side-menu-widget-item-checkbox:not([checked]) .checkbox-check,
 .side-menu-widget-item-checkbox:not([checked]) + vbox {
   opacity: 0.3;
 }
 
 .side-menu-widget-item:not(.selected) .checkbox-check {
-  filter: var(--icon-filter);
+  filter: var(--theme-icon-filter);
 }
 
 /* Make sure icon is white when the item is selected */
 .side-menu-widget-item.selected .checkbox-check {
   filter: invert(1);
 }
 
 /* Shader source editors */

--- a/devtools/client/themes/styleeditor.css
+++ b/devtools/client/themes/styleeditor.css
@@ -168,17 +168,17 @@ li.error > .stylesheet-info > .styleshee
   margin: 0 8px;
   background-image: url(images/item-toggle.svg);
   background-repeat: no-repeat;
   background-clip: content-box;
   background-position: center;
   background-size: 16px;
   width: 24px;
   height: 40px;
-  filter: var(--icon-filter);
+  filter: var(--theme-icon-filter);
 }
 
 .disabled > .stylesheet-enabled {
   opacity: 0.3;
 }
 
 /* Invert the toggle icon in the active row for light theme */
 .theme-light .splitview-nav > li.splitview-active .stylesheet-enabled {

--- a/devtools/client/themes/toolbars.css
+++ b/devtools/client/themes/toolbars.css
@@ -9,44 +9,35 @@
   --searchbox-border-color: #ffbf00;
   --searcbox-no-match-background-color: #ffe5e5;
   --searcbox-no-match-border-color: #e52e2e;
 
   --magnifying-glass-image: url(chrome://devtools/skin/images/search.svg);
   --filter-image: url(chrome://devtools/skin/images/filter.svg);
   --tool-options-image: url(chrome://devtools/skin/images/tool-options.svg);
 
-  --icon-filter: none;
-  --checked-icon-filter: url(chrome://devtools/skin/images/filters.svg#checked-icon-state);
-
   --separator-border-image: linear-gradient(transparent 4px, rgba(0,0,0,.1) 4px, rgba(0,0,0,.1) calc(100% - 4px), transparent calc(100% - 4px));
 }
 
 .theme-dark {
   --searchbox-background-color: #4d4222;
   --searchbox-border-color: #d99f2b;
   --searcbox-no-match-background-color: #402325;
   --searcbox-no-match-border-color: #cc3d3d;
 
   --magnifying-glass-image: url(chrome://devtools/skin/images/search.svg);
   --filter-image: url(chrome://devtools/skin/images/filter.svg);
   --tool-options-image: url(chrome://devtools/skin/images/tool-options.svg);
 
-  --icon-filter: invert(1);
-  --checked-icon-filter: url(chrome://devtools/skin/images/filters.svg#dark-theme-checked-icon-state);
-
-  --separator-border-image: linear-gradient(transparent 4px, rgba(100%,100%,100%,.2) 4px, rgba(100%,100%,100%,.2) calc(100% - 4px), transparent calc(100% - 4px))
+  --separator-border-image: linear-gradient(transparent 4px, rgba(100%,100%,100%,.2) 4px, rgba(100%,100%,100%,.2) calc(100% - 4px), transparent calc(100% - 4px));
 }
 
 .theme-firebug {
   --magnifying-glass-image: url(chrome://devtools/skin/images/search.svg);
   --tool-options-image: url(chrome://devtools/skin/images/firebug/tool-options.svg);
-
-  --icon-filter: none;
-  --checked-icon-filter: none;
 }
 
 
 /* Toolbars */
 .devtools-toolbar,
 .devtools-sidebar-tabs tabs {
   -moz-appearance: none;
   padding: 0;
@@ -196,17 +187,17 @@
 .devtools-toolbarbutton > image,
 .devtools-button::before,
 .scrollbutton-up > .toolbarbutton-icon,
 .scrollbutton-down > .toolbarbutton-icon,
 #black-boxed-message-button .button-icon,
 #canvas-debugging-empty-notice-button .button-icon,
 #toggle-breakpoints[checked] > image,
 .event-tooltip-debugger-icon {
-  filter: var(--icon-filter);
+  filter: var(--theme-icon-filter);
 }
 
 .hidden-labels-box:not(.visible) > label,
 .hidden-labels-box.visible ~ .hidden-labels-box > label:last-child {
   display: none;
 }
 
 .devtools-invisible-splitter {

--- a/devtools/client/themes/toolbox.css
+++ b/devtools/client/themes/toolbox.css
@@ -139,52 +139,47 @@
 .theme-firebug .devtools-tab {
   -moz-box-flex: initial;
 }
 
 .devtools-tab {
   color: var(--theme-toolbar-color);
 }
 
-.theme-dark .devtools-tab:hover {
-  color: #ced3d9;
-}
-
 .devtools-tab:hover {
   background-color: var(--theme-toolbar-hover);
 }
 
-.theme-dark .devtools-tab:hover:active {
-  color: var(--theme-selection-color);
-}
-
 .devtools-tab:hover:active {
   background-color: var(--theme-toolbar-hover-active);
 }
 
 .devtools-tab:not(.selected).highlighted {
   background-color: var(--theme-toolbar-background-alt);
 }
 
+.devtools-tab.selected {
+  color: var(--theme-toolbar-selected-color);
+}
+
 /* Display execution pointer in the Debugger tab to indicate
    that the debugger is paused. */
 .theme-firebug #toolbox-tab-jsdebugger.devtools-tab:not(.selected).highlighted {
   background-color: rgba(89, 178, 234, .2);
   background-image: url(chrome://devtools/skin/images/firebug/tool-debugger-paused.svg);
   background-repeat: no-repeat;
   padding-left: 13px !important;
   background-position: 3px 6px;
 }
 
 .devtools-tab > img {
   border: none;
   margin: 0;
   margin-inline-start: 10px;
   margin-inline-end: 5px;
-  opacity: 0.8;
   max-height: 16px;
   width: 16px; /* Prevents collapse during theme switching */
   vertical-align: text-top;
   flex-shrink: 0;
 }
 
 /* Don't apply any filter to non-invertable command button icons */
 .command-button:not(.command-button-invertable),
@@ -195,20 +190,19 @@
   filter: none;
 }
 
 .devtools-tab > label {
   white-space: nowrap;
   margin: 0 4px;
 }
 
-.devtools-tab:hover > img,
-.devtools-tab:active > img,
-.devtools-tab.selected > img {
-  opacity: 1;
+/* Apply selected icon filter to `invertable` icons */
+.devtools-tab.selected.icon-invertable > img {
+  filter: var(--theme-icon-selected-filter) !important;
 }
 
 .devtools-tab:not(.highlighted) > .highlighted-icon,
 .devtools-tab.selected > .highlighted-icon,
 .devtools-tab:not(.selected).highlighted > .default-icon {
   display: none;
 }
 

--- a/devtools/client/themes/variables.css
+++ b/devtools/client/themes/variables.css
@@ -20,20 +20,21 @@
   --theme-body-background: white;
   --theme-sidebar-background: white;
   --theme-contrast-background: #e6b064;
 
   /* Toolbar */
   --theme-tab-toolbar-background: var(--grey-10);
   --theme-toolbar-background: var(--grey-10);
   --theme-toolbar-color: var(--grey-90);
+  --theme-toolbar-selected-color: var(--blue-60);
   --theme-toolbar-background-hover: rgba(221, 225, 228, 0.66);
   --theme-toolbar-background-alt: #f5f5f5;
-  --theme-toolbar-hover: rgba(170, 170, 170, .2);
-  --theme-toolbar-hover-active: rgba(170, 170, 170, .4);
+  --theme-toolbar-hover: var(--grey-20);
+  --theme-toolbar-hover-active: var(--grey-20);
 
   /* Selection */
   --theme-selection-background: var(--blue-55);
   --theme-selection-background-hover: #F0F9FE;
   --theme-selection-color: #f5f7fa;
 
   /* Border color that splits the toolbars/panels/headers.
    * This needs to be sync with commandline.css and commandline-browser.css. */
@@ -75,16 +76,21 @@
   --theme-graphs-grey: #cccccc;
   --theme-graphs-full-red: #f00;
   --theme-graphs-full-blue: #00f;
 
   /* Images */
   --theme-pane-collapse-image: url(chrome://devtools/skin/images/pane-collapse.svg);
   --theme-pane-expand-image: url(chrome://devtools/skin/images/pane-expand.svg);
 
+  /* Icon filters */
+  --theme-icon-filter: url(chrome://devtools/skin/images/filters.svg#icon-normal-light);
+  --theme-icon-selected-filter: url(chrome://devtools/skin/images/filters.svg#icon-selected-light);
+  --theme-icon-checked-filter: url(chrome://devtools/skin/images/filters.svg#icon-checked-light);
+
   /* Tooltips */
   --theme-tooltip-border: #d9e1e8;
   --theme-tooltip-background: rgba(255, 255, 255, .9);
   --theme-tooltip-shadow: rgba(155, 155, 155, 0.26);
 
   /* Command line */
   --theme-command-line-image: url(chrome://devtools/skin/images/commandline-icon.svg#light-theme);
   --theme-command-line-image-focus: url(chrome://devtools/skin/images/commandline-icon.svg#light-theme-focus);
@@ -96,20 +102,21 @@
   --theme-body-background: var(--grey-80);
   --theme-sidebar-background: var(--grey-90);
   --theme-contrast-background: #ffb35b;
 
   /* Toolbar */
   --theme-tab-toolbar-background: var(--grey-90);
   --theme-toolbar-background: var(--grey-90);
   --theme-toolbar-color: var(--grey-40);
+  --theme-toolbar-selected-color: white;
   --theme-toolbar-background-hover: #20232B;
   --theme-toolbar-background-alt: #2F343E;
-  --theme-toolbar-hover: rgba(110, 120, 130, 0.1);
-  --theme-toolbar-hover-active: rgba(110, 120, 130, 0.2);
+  --theme-toolbar-hover: #252526;
+  --theme-toolbar-hover-active: #252526;
 
   /* Selection */
   --theme-selection-background: #204E8A;
   --theme-selection-background-hover: #353B48;
   --theme-selection-color: #f5f7fa;
 
   /* Border color that splits the toolbars/panels/headers.
    * This needs to be sync with commandline.css and commandline-browser.css. */
@@ -151,16 +158,21 @@
   --theme-graphs-grey: #757873;
   --theme-graphs-full-red: #f00;
   --theme-graphs-full-blue: #00f;
 
   /* Images */
   --theme-pane-collapse-image: url(chrome://devtools/skin/images/pane-collapse.svg);
   --theme-pane-expand-image: url(chrome://devtools/skin/images/pane-expand.svg);
 
+  /* Icon filters */
+  --theme-icon-filter: url(chrome://devtools/skin/images/filters.svg#icon-normal-dark);
+  --theme-icon-selected-filter: url(chrome://devtools/skin/images/filters.svg#icon-selected-dark);
+  --theme-icon-checked-filter: url(chrome://devtools/skin/images/filters.svg#icon-checked-dark);
+
   /* Tooltips */
   --theme-tooltip-border: #434850;
   --theme-tooltip-background: rgba(19, 28, 38, .9);
   --theme-tooltip-shadow: rgba(25, 25, 25, 0.76);
 
   /* Command line */
   --theme-command-line-image: url(chrome://devtools/skin/images/commandline-icon.svg#dark-theme);
   --theme-command-line-image-focus: url(chrome://devtools/skin/images/commandline-icon.svg#dark-theme-focus);
@@ -209,16 +221,21 @@
   --theme-graphs-grey: #cccccc;
   --theme-graphs-full-red: #f00;
   --theme-graphs-full-blue: #00f;
 
   /* Images */
   --theme-pane-collapse-image: url(chrome://devtools/skin/images/firebug/pane-collapse.svg);
   --theme-pane-expand-image: url(chrome://devtools/skin/images/firebug/pane-expand.svg);
 
+  /* Icon filters */
+  --theme-icon-filter: none;
+  --theme-icon-selected-filter: none;
+  --theme-icon-checked-filter: none;
+
   /* Font size */
   --theme-toolbar-font-size: 12px;
 
   /* Header */
   --theme-header-background: #F0F0F0 linear-gradient(to top,
                                                      rgba(0, 0, 0, 0.1),
                                                      transparent) repeat-x;
 
@@ -248,17 +265,17 @@
   --theme-focus-border-color-textbox: #0675d3;
   --theme-textbox-box-shadow: rgba(97,181,255,.75);
 
   /* For accessibility purposes we want to enhance the focus styling. This
    * should improve keyboard navigation usability. */
   --theme-focus-outline: 1px dotted var(--theme-focus-outline-color);
   --theme-focus-box-shadow-textbox: 0 0 0 1px var(--theme-textbox-box-shadow);
 
-  --toolbarbutton-background: rgba(110,120,130,0.1);
+  --toolbarbutton-background: var(--theme-toolbar-hover);
   --toolbarbutton-border-color: transparent;
   --toolbarbutton-hover-background: rgba(110,120,130,0.2);
   --toolbarbutton-hover-border-color: var(--toolbarbutton-border-color);
   --toolbarbutton-checked-background: var(--theme-selection-background);
   --toolbarbutton-checked-color: var(--theme-selection-color);
   --toolbarbutton-checked-border-color: var(--toolbarbutton-border-color);
 
   /* The photon animation curve */

--- a/dom/base/PostMessageEvent.cpp
+++ b/dom/base/PostMessageEvent.cpp
@@ -138,60 +138,86 @@ PostMessageEvent::Run()
         nsContentUtils::eDOM_PROPERTIES,
         "TargetPrincipalDoesNotMatch",
         params, ArrayLength(params));
 
       return NS_OK;
     }
   }
 
-  ErrorResult rv;
+  IgnoredErrorResult rv;
   JS::Rooted<JS::Value> messageData(cx);
-  nsCOMPtr<nsPIDOMWindowInner> window = targetWindow->AsInner();
+  nsCOMPtr<mozilla::dom::EventTarget> eventTarget = do_QueryObject(targetWindow);
 
-  Read(window, cx, &messageData, rv);
+  Read(targetWindow->AsInner(), cx, &messageData, rv);
   if (NS_WARN_IF(rv.Failed())) {
-    return rv.StealNSResult();
+    DispatchError(cx, targetWindow, eventTarget);
+    return NS_OK;
   }
 
   // Create the event
-  nsCOMPtr<mozilla::dom::EventTarget> eventTarget = do_QueryObject(targetWindow);
-  RefPtr<MessageEvent> event =
-    new MessageEvent(eventTarget, nullptr, nullptr);
+  RefPtr<MessageEvent> event = new MessageEvent(eventTarget, nullptr, nullptr);
 
 
   Nullable<WindowProxyOrMessagePortOrServiceWorker> source;
   source.SetValue().SetAsWindowProxy() = mSource ? mSource->AsOuter() : nullptr;
 
   Sequence<OwningNonNull<MessagePort>> ports;
   if (!TakeTransferredPortsAsSequence(ports)) {
-    return NS_ERROR_OUT_OF_MEMORY;
+    DispatchError(cx, targetWindow, eventTarget);
+    return NS_OK;
   }
 
   event->InitMessageEvent(nullptr, NS_LITERAL_STRING("message"),
                           false /*non-bubbling */, false /*cancelable */,
                           messageData, mCallerOrigin,
                           EmptyString(), source, ports);
 
+  Dispatch(targetWindow, event);
+  return NS_OK;
+}
+
+void
+PostMessageEvent::DispatchError(JSContext* aCx, nsGlobalWindow* aTargetWindow,
+                                mozilla::dom::EventTarget* aEventTarget)
+{
+  RootedDictionary<MessageEventInit> init(aCx);
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mOrigin = mCallerOrigin;
+
+  if (mSource) {
+    init.mSource.SetValue().SetAsWindowProxy() = mSource->AsOuter();
+  }
+
+  RefPtr<Event> event =
+    MessageEvent::Constructor(aEventTarget, NS_LITERAL_STRING("messageerror"),
+                              init);
+  Dispatch(aTargetWindow, event);
+}
+
+void
+PostMessageEvent::Dispatch(nsGlobalWindow* aTargetWindow, Event* aEvent)
+{
   // We can't simply call dispatchEvent on the window because doing so ends
   // up flipping the trusted bit on the event, and we don't want that to
   // happen because then untrusted content can call postMessage on a chrome
   // window if it can get a reference to it.
 
-  nsIPresShell *shell = targetWindow->GetExtantDoc()->GetShell();
+  nsIPresShell *shell = aTargetWindow->GetExtantDoc()->GetShell();
   RefPtr<nsPresContext> presContext;
-  if (shell)
+  if (shell) {
     presContext = shell->GetPresContext();
+  }
 
-  event->SetTrusted(mTrustedCaller);
-  WidgetEvent* internalEvent = event->WidgetEventPtr();
+  aEvent->SetTrusted(mTrustedCaller);
+  WidgetEvent* internalEvent = aEvent->WidgetEventPtr();
 
   nsEventStatus status = nsEventStatus_eIgnore;
-  EventDispatcher::Dispatch(window,
+  EventDispatcher::Dispatch(aTargetWindow->AsInner(),
                             presContext,
                             internalEvent,
-                            static_cast<dom::Event*>(event.get()),
+                            aEvent,
                             &status);
-  return NS_OK;
 }
 
 } // namespace dom
 } // namespace mozilla

--- a/dom/base/PostMessageEvent.h
+++ b/dom/base/PostMessageEvent.h
@@ -35,16 +35,23 @@ public:
                    nsGlobalWindow* aTargetWindow,
                    nsIPrincipal* aProvidedPrincipal,
                    nsIDocument* aSourceDocument,
                    bool aTrustedCaller);
 
 private:
   ~PostMessageEvent();
 
+  void
+  Dispatch(nsGlobalWindow* aTargetWindow, Event* aEvent);
+
+  void
+  DispatchError(JSContext* aCx, nsGlobalWindow* aTargetWindow,
+                mozilla::dom::EventTarget* aEventTarget);
+
   RefPtr<nsGlobalWindow> mSource;
   nsString mCallerOrigin;
   RefPtr<nsGlobalWindow> mTargetWindow;
   nsCOMPtr<nsIPrincipal> mProvidedPrincipal;
   nsCOMPtr<nsIDocument> mSourceDocument;
   bool mTrustedCaller;
 };
 

--- a/dom/base/nsCopySupport.cpp
+++ b/dom/base/nsCopySupport.cpp
@@ -840,18 +840,26 @@ nsCopySupport::FireClipboardEvent(EventM
     doDefault = (status != nsEventStatus_eConsumeNoDefault);
   }
 
   // When this function exits, the event dispatch is over. We want to disconnect
   // our DataTransfer, which means setting its mode to `Protected` and clearing
   // all stored data, before we return.
   auto clearAfter = MakeScopeExit([&] {
     if (clipboardData) {
-      clipboardData->SetMode(DataTransfer::Mode::Protected);
-      clipboardData->ClearAll();
+      clipboardData->Disconnect();
+
+      // NOTE: Disconnect may not actually clear the DataTransfer if the
+      // dom.events.dataTransfer.protected.enabled pref is not on, so we make
+      // sure we clear here, as not clearing could provide the DataTransfer
+      // access to information from the system clipboard at an arbitrary point
+      // in the future.
+      if (originalEventMessage == ePaste) {
+        clipboardData->ClearAll();
+      }
     }
   });
 
   // No need to do anything special during a paste. Either an event listener
   // took care of it and cancelled the event, or the caller will handle it.
   // Return true to indicate that the event wasn't cancelled.
   if (originalEventMessage == ePaste) {
     if (aActionTaken) {

--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -915,16 +915,17 @@ GK_ATOM(onlevelchange, "onlevelchange")
 GK_ATOM(onLoad, "onLoad")
 GK_ATOM(onload, "onload")
 GK_ATOM(onloading, "onloading")
 GK_ATOM(onloadingdone, "onloadingdone")
 GK_ATOM(onloadingerror, "onloadingerror")
 GK_ATOM(onpopstate, "onpopstate")
 GK_ATOM(only, "only")               // this one is not an event
 GK_ATOM(onmessage, "onmessage")
+GK_ATOM(onmessageerror, "onmessageerror")
 GK_ATOM(onmousedown, "onmousedown")
 GK_ATOM(onmouseenter, "onmouseenter")
 GK_ATOM(onmouseleave, "onmouseleave")
 GK_ATOM(onmouselongtap, "onmouselongtap")
 GK_ATOM(onmousemove, "onmousemove")
 GK_ATOM(onmouseout, "onmouseout")
 GK_ATOM(onmouseover, "onmouseover")
 GK_ATOM(onMozMouseHittest, "onMozMouseHittest")

--- a/dom/bindings/BindingUtils.h
+++ b/dom/bindings/BindingUtils.h
@@ -2820,17 +2820,17 @@ ToSupportsIsOnPrimaryInheritanceChain(T*
 }
 
 // Get the size of allocated memory to associate with a binding JSObject for a
 // native object. This is supplied to the JS engine to allow it to schedule GC
 // when necessary.
 //
 // This function supplies a default value and is overloaded for specific native
 // object types.
-inline uint64_t
+inline size_t
 BindingJSObjectMallocBytes(void *aNativePtr)
 {
   return 0;
 }
 
 // The BindingJSObjectCreator class is supposed to be used by a caller that
 // wants to create and initialise a binding JSObject. After initialisation has
 // been successfully completed it should call ForgetObject().
@@ -2869,34 +2869,34 @@ public:
     aReflector.set(js::NewProxyObject(aCx, aHandler, aExpandoValue, aProto,
                                       options));
     if (aReflector) {
       js::SetProxyReservedSlot(aReflector, DOM_OBJECT_SLOT, JS::PrivateValue(aNative));
       mNative = aNative;
       mReflector = aReflector;
     }
 
-    if (uint64_t mallocBytes = BindingJSObjectMallocBytes(aNative)) {
+    if (size_t mallocBytes = BindingJSObjectMallocBytes(aNative)) {
       JS_updateMallocCounter(aCx, mallocBytes);
     }
   }
 
   void
   CreateObject(JSContext* aCx, const JSClass* aClass,
                JS::Handle<JSObject*> aProto,
                T* aNative, JS::MutableHandle<JSObject*> aReflector)
   {
     aReflector.set(JS_NewObjectWithGivenProto(aCx, aClass, aProto));
     if (aReflector) {
       js::SetReservedSlot(aReflector, DOM_OBJECT_SLOT, JS::PrivateValue(aNative));
       mNative = aNative;
       mReflector = aReflector;
     }
 
-    if (uint64_t mallocBytes = BindingJSObjectMallocBytes(aNative)) {
+    if (size_t mallocBytes = BindingJSObjectMallocBytes(aNative)) {
       JS_updateMallocCounter(aCx, mallocBytes);
     }
   }
 
   void
   InitializationSucceeded()
   {
     void* dummy;

--- a/dom/broadcastchannel/BroadcastChannel.h
+++ b/dom/broadcastchannel/BroadcastChannel.h
@@ -63,16 +63,17 @@ public:
   }
 
   void PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
                    ErrorResult& aRv);
 
   void Close();
 
   IMPL_EVENT_HANDLER(message)
+  IMPL_EVENT_HANDLER(messageerror)
 
   void Shutdown();
 
 private:
   BroadcastChannel(nsPIDOMWindowInner* aWindow,
                    const PrincipalInfo& aPrincipalInfo,
                    const nsACString& aOrigin,
                    const nsAString& aChannel);

--- a/dom/broadcastchannel/BroadcastChannelChild.cpp
+++ b/dom/broadcastchannel/BroadcastChannelChild.cpp
@@ -75,20 +75,20 @@ BroadcastChannelChild::RecvNotify(const 
   if (!globalObject || !jsapi.Init(globalObject)) {
     NS_WARNING("Failed to initialize AutoJSAPI object.");
     return IPC_OK();
   }
 
   JSContext* cx = jsapi.cx();
   JS::Rooted<JS::Value> value(cx, JS::NullValue());
   if (cloneData.DataLength()) {
-    ErrorResult rv;
+    IgnoredErrorResult rv;
     cloneData.Read(cx, &value, rv);
     if (NS_WARN_IF(rv.Failed())) {
-      rv.SuppressException();
+      DispatchError(cx);
       return IPC_OK();
     }
   }
 
   RootedDictionary<MessageEventInit> init(cx);
   init.mBubbles = false;
   init.mCancelable = false;
   init.mOrigin = mOrigin;
@@ -106,10 +106,26 @@ BroadcastChannelChild::RecvNotify(const 
 }
 
 void
 BroadcastChannelChild::ActorDestroy(ActorDestroyReason aWhy)
 {
   mActorDestroyed = true;
 }
 
+void
+BroadcastChannelChild::DispatchError(JSContext* aCx)
+{
+  RootedDictionary<MessageEventInit> init(aCx);
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mOrigin = mOrigin;
+
+  RefPtr<Event> event =
+    MessageEvent::Constructor(mBC, NS_LITERAL_STRING("messageerror"), init);
+  event->SetTrusted(true);
+
+  bool dummy;
+  mBC->DispatchEvent(event, &dummy);
+}
+
 } // namespace dom
 } // namespace mozilla

--- a/dom/broadcastchannel/BroadcastChannelChild.h
+++ b/dom/broadcastchannel/BroadcastChannelChild.h
@@ -39,16 +39,18 @@ public:
   }
 
 private:
   explicit BroadcastChannelChild(const nsACString& aOrigin);
   ~BroadcastChannelChild();
 
   virtual void ActorDestroy(ActorDestroyReason aWhy) override;
 
+  void DispatchError(JSContext* aCx);
+
   // This raw pointer is actually the parent object.
   // It's set to null when the parent object is deleted.
   BroadcastChannel* mBC;
 
   nsString mOrigin;
 
   bool mActorDestroyed;
 };

--- a/dom/browser-element/mochitest/browserElement_Iconchange.js
+++ b/dom/browser-element/mochitest/browserElement_Iconchange.js
@@ -2,16 +2,17 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Test that the onmozbrowsericonchange event works.
 "use strict";
 
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
+browserElementTestHelpers.allowTopLevelDataURINavigation();
 
 function createHtml(link) {
   return 'data:text/html,<html><head>' + link + '<body></body></html>';
 }
 
 function createLink(name, sizes, rel) {
   var s = sizes ? 'sizes="' + sizes + '"' : '';
   if (!rel) {

--- a/dom/browser-element/mochitest/browserElement_Manifestchange.js
+++ b/dom/browser-element/mochitest/browserElement_Manifestchange.js
@@ -2,16 +2,17 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Test that the onmozbrowsermanifestchange event works.
 "use strict";
 
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
+browserElementTestHelpers.allowTopLevelDataURINavigation();
 
 function createHtml(manifest) {
   return 'data:text/html,<html xmlns:xml="http://www.w3.org/XML/1998/namespace"><head>' + manifest + '<body></body></html>';
 }
 
 function createManifest(href) {
   return '<link rel="manifest" href="' + href + '">';
 }

--- a/dom/browser-element/mochitest/browserElement_Metachange.js
+++ b/dom/browser-element/mochitest/browserElement_Metachange.js
@@ -2,16 +2,17 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Test that the onmozbrowsermetachange event works.
 "use strict";
 
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
+browserElementTestHelpers.allowTopLevelDataURINavigation();
 
 function createHtml(meta) {
   return 'data:text/html,<html xmlns:xml="http://www.w3.org/XML/1998/namespace"><head>' + meta + '<body></body></html>';
 }
 
 function createHtmlWithLang(meta, lang) {
   return 'data:text/html,<html xmlns:xml="http://www.w3.org/XML/1998/namespace" lang="' + lang + '"><head>' + meta + '<body></body></html>';
 }

--- a/dom/browser-element/mochitest/browserElement_Opensearch.js
+++ b/dom/browser-element/mochitest/browserElement_Opensearch.js
@@ -2,16 +2,17 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // Test that the onmozbrowseropensearch event works.
 "use strict";
 
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
+browserElementTestHelpers.allowTopLevelDataURINavigation();
 
 function createHtml(link) {
   return 'data:text/html,<html><head>' + link + '<body></body></html>';
 }
 
 function createLink(name) {
   return '<link rel="search" title="Test OpenSearch" type="application/opensearchdescription+xml" href="http://example.com/' + name + '.xml">';
 }

--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -1784,22 +1784,16 @@ CanvasRenderingContext2D::RegisterAlloca
   // PeristentBufferProvider, rather than here.
   static bool registered = false;
   // FIXME: Disable the reporter for now, see bug 1241865
   if (!registered && false) {
     registered = true;
     RegisterStrongMemoryReporter(new Canvas2dPixelsReporter());
   }
 
-  gCanvasAzureMemoryUsed += mWidth * mHeight * 4;
-  JSContext* context = nsContentUtils::GetCurrentJSContext();
-  if (context) {
-    JS_updateMallocCounter(context, mWidth * mHeight * 4);
-  }
-
   JSObject* wrapper = GetWrapperPreserveColor();
   if (wrapper) {
     CycleCollectedJSRuntime::Get()->
       AddZoneWaitingForGC(JS::GetObjectZone(wrapper));
   }
 }
 
 static already_AddRefed<LayerManager>
@@ -6549,10 +6543,16 @@ CanvasPath::EnsurePathBuilder() const
   }
 
   // if there is not pathbuilder, there must be a path
   MOZ_ASSERT(mPath);
   mPathBuilder = mPath->CopyToBuilder();
   mPath = nullptr;
 }
 
+size_t
+BindingJSObjectMallocBytes(CanvasRenderingContext2D* aContext)
+{
+  return aContext->GetWidth() * aContext->GetHeight() * 4;
+}
+
 } // namespace dom
 } // namespace mozilla

--- a/dom/canvas/CanvasRenderingContext2D.h
+++ b/dom/canvas/CanvasRenderingContext2D.h
@@ -1164,12 +1164,14 @@ protected:
     if (aPerCSSPixel)
       *aPerCSSPixel = cssPixel;
   }
 
   friend struct CanvasBidiProcessor;
   friend class CanvasDrawObserver;
 };
 
+size_t BindingJSObjectMallocBytes(CanvasRenderingContext2D* aContext);
+
 } // namespace dom
 } // namespace mozilla
 
 #endif /* CanvasRenderingContext2D_h */

--- a/dom/canvas/ImageBitmap.cpp
+++ b/dom/canvas/ImageBitmap.cpp
@@ -30,55 +30,16 @@ NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Im
 NS_IMPL_CYCLE_COLLECTING_ADDREF(ImageBitmap)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(ImageBitmap)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ImageBitmap)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
 /*
- * This helper function is used to notify DOM that aBytes memory is allocated
- * here so that we could trigger GC appropriately.
- */
-static void
-RegisterAllocation(nsIGlobalObject* aGlobal, size_t aBytes)
-{
-  AutoJSAPI jsapi;
-  if (jsapi.Init(aGlobal)) {
-    JS_updateMallocCounter(jsapi.cx(), aBytes);
-  }
-}
-
-static void
-RegisterAllocation(nsIGlobalObject* aGlobal, SourceSurface* aSurface)
-{
-  // Calculate how many bytes are used.
-  const int bytesPerPixel = BytesPerPixel(aSurface->GetFormat());
-  const size_t bytes =
-    aSurface->GetSize().height * aSurface->GetSize().width * bytesPerPixel;
-
-  // Register.
-  RegisterAllocation(aGlobal, bytes);
-}
-
-static void
-RegisterAllocation(nsIGlobalObject* aGlobal, layers::Image* aImage)
-{
-  // Calculate how many bytes are used.
-  if (aImage->GetFormat() == mozilla::ImageFormat::PLANAR_YCBCR) {
-    RegisterAllocation(aGlobal, aImage->AsPlanarYCbCrImage()->GetDataSize());
-  } else if (aImage->GetFormat() == mozilla::ImageFormat::NV_IMAGE) {
-    RegisterAllocation(aGlobal, aImage->AsNVImage()->GetBufferSize());
-  } else {
-    RefPtr<SourceSurface> surface = aImage->GetAsSourceSurface();
-    RegisterAllocation(aGlobal, surface);
-  }
-}
-
-/*
  * If either aRect.width or aRect.height are negative, then return a new IntRect
  * which represents the same rectangle as the aRect does but with positive width
  * and height.
  */
 static IntRect
 FixUpNegativeDimension(const IntRect& aRect, ErrorResult& aRv)
 {
   gfx::IntRect rect = aRect;
@@ -439,16 +400,17 @@ ImageBitmap::ImageBitmap(nsIGlobalObject
                          gfxAlphaType aAlphaType)
   : mParent(aGlobal)
   , mData(aData)
   , mSurface(nullptr)
   , mDataWrapper(new ImageUtils(mData))
   , mPictureRect(0, 0, aData->GetSize().width, aData->GetSize().height)
   , mAlphaType(aAlphaType)
   , mIsCroppingAreaOutSideOfSourceImage(false)
+  , mAllocatedImageData(false)
 {
   MOZ_ASSERT(aData, "aData is null in ImageBitmap constructor.");
 }
 
 ImageBitmap::~ImageBitmap()
 {
 }
 
@@ -706,18 +668,17 @@ ImageBitmap::ToCloneData() const
 /* static */ already_AddRefed<ImageBitmap>
 ImageBitmap::CreateFromCloneData(nsIGlobalObject* aGlobal,
                                  ImageBitmapCloneData* aData)
 {
   RefPtr<layers::Image> data = CreateImageFromSurface(aData->mSurface);
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, aData->mAlphaType);
 
-  // Report memory allocation.
-  RegisterAllocation(aGlobal, aData->mSurface);
+  ret->mAllocatedImageData = true;
 
   ret->mIsCroppingAreaOutSideOfSourceImage =
     aData->mIsCroppingAreaOutSideOfSourceImage;
 
   ErrorResult rv;
   ret->SetPictureRect(aData->mPictureRect, rv);
   return ret.forget();
 }
@@ -744,18 +705,17 @@ ImageBitmap::CreateFromOffscreenCanvas(n
     return nullptr;
   }
 
   RefPtr<layers::Image> data =
     CreateImageFromSurface(surface);
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data);
 
-  // Report memory allocation.
-  RegisterAllocation(aGlobal, surface);
+  ret->mAllocatedImageData = true;
 
   return ret.forget();
 }
 
 /* static */ already_AddRefed<ImageBitmap>
 ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, HTMLImageElement& aImageEl,
                             const Maybe<IntRect>& aCropRect, ErrorResult& aRv)
 {
@@ -891,19 +851,18 @@ ImageBitmap::CreateInternal(nsIGlobalObj
 
   if (NS_WARN_IF(!data)) {
     aRv.Throw(NS_ERROR_NOT_AVAILABLE);
     return nullptr;
   }
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data);
 
-  // Report memory allocation if needed.
   if (needToReportMemoryAllocation) {
-    RegisterAllocation(aGlobal, croppedSurface);
+    ret->mAllocatedImageData = true;
   }
 
   // Set the picture rectangle.
   if (ret && aCropRect.isSome()) {
     ret->SetPictureRect(cropRect, aRv);
   }
 
   // Set mIsCroppingAreaOutSideOfSourceImage.
@@ -960,18 +919,17 @@ ImageBitmap::CreateInternal(nsIGlobalObj
   if (NS_WARN_IF(!data)) {
     aRv.Throw(NS_ERROR_NOT_AVAILABLE);
     return nullptr;
   }
 
   // Create an ImageBimtap.
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, alphaType);
 
-  // Report memory allocation.
-  RegisterAllocation(aGlobal, data);
+  ret->mAllocatedImageData = true;
 
   // The cropping information has been handled in the CreateImageFromRawData()
   // function.
 
   // Set mIsCroppingAreaOutSideOfSourceImage.
   ret->SetIsCroppingAreaOutSideOfSourceImage(imageSize, aCropRect);
 
   return ret.forget();
@@ -1004,18 +962,17 @@ ImageBitmap::CreateInternal(nsIGlobalObj
 
   if (NS_WARN_IF(!data)) {
     aRv.Throw(NS_ERROR_NOT_AVAILABLE);
     return nullptr;
   }
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data);
 
-  // Report memory allocation.
-  RegisterAllocation(aGlobal, surface);
+  ret->mAllocatedImageData = true;
 
   // Set the picture rectangle.
   if (ret && aCropRect.isSome()) {
     ret->SetPictureRect(aCropRect.ref(), aRv);
   }
 
   // Set mIsCroppingAreaOutSideOfSourceImage.
   ret->SetIsCroppingAreaOutSideOfSourceImage(surface->GetSize(), aCropRect);
@@ -1249,18 +1206,17 @@ protected:
       imageBitmap->SetPictureRect(mCropRect.ref(), rv);
 
       if (rv.Failed()) {
         mPromise->MaybeReject(rv);
         return false;
       }
     }
 
-    // Report memory allocation.
-    RegisterAllocation(mGlobalObject, imageBitmap->mData);
+    imageBitmap->mAllocatedImageData = true;
 
     mPromise->MaybeResolve(imageBitmap);
     return true;
   }
 
   // Will return null on failure.  In that case, mPromise will already
   // be rejected with the right thing.
   virtual already_AddRefed<ImageBitmap> CreateImageBitmap() = 0;
@@ -1539,18 +1495,17 @@ ImageBitmap::ReadStructuredClone(JSConte
       error.SuppressException();
       return nullptr;
     }
 
     if (!GetOrCreateDOMReflector(aCx, imageBitmap, &value)) {
       return nullptr;
     }
 
-    // Report memory allocation.
-    RegisterAllocation(aParent, aClonedSurfaces[aIndex]);
+    imageBitmap->mAllocatedImageData = true;
   }
 
   return &(value.toObject());
 }
 
 /*static*/ bool
 ImageBitmap::WriteStructuredClone(JSStructuredCloneWriter* aWriter,
                                   nsTArray<RefPtr<DataSourceSurface>>& aClonedSurfaces,
@@ -2139,26 +2094,52 @@ ImageBitmap::Create(nsIGlobalObject* aGl
     return promise.forget();
   }
 
   // Create an ImageBimtap.
   // Assume the data from an external buffer is not alpha-premultiplied.
   RefPtr<ImageBitmap> imageBitmap = new ImageBitmap(aGlobal, data,
                                                     gfxAlphaType::NonPremult);
 
-  // Report memory allocation.
-  RegisterAllocation(aGlobal, data);
+  imageBitmap->mAllocatedImageData = true;
 
   // We don't need to call SetPictureRect() here because there is no cropping
   // supported and the ImageBitmap's mPictureRect is the size of the source
   // image in default
 
   // We don't need to set mIsCroppingAreaOutSideOfSourceImage here because there
   // is no cropping supported and the mIsCroppingAreaOutSideOfSourceImage is
   // false in default.
 
   AsyncFulfillImageBitmapPromise(promise, imageBitmap);
 
   return promise.forget();
 }
 
+size_t
+ImageBitmap::GetAllocatedSize() const
+{
+  if (!mAllocatedImageData) {
+    return 0;
+  }
+
+  // Calculate how many bytes are used.
+  if (mData->GetFormat() == mozilla::ImageFormat::PLANAR_YCBCR) {
+    return mData->AsPlanarYCbCrImage()->GetDataSize();
+  }
+
+  if (mData->GetFormat() == mozilla::ImageFormat::NV_IMAGE) {
+    return mData->AsNVImage()->GetBufferSize();
+  }
+
+  RefPtr<SourceSurface> surface = mData->GetAsSourceSurface();
+  const int bytesPerPixel = BytesPerPixel(surface->GetFormat());
+  return surface->GetSize().height * surface->GetSize().width * bytesPerPixel;
+}
+
+size_t
+BindingJSObjectMallocBytes(ImageBitmap* aBitmap)
+{
+  return aBitmap->GetAllocatedSize();
+}
+
 } // namespace dom
 } // namespace mozilla

--- a/dom/canvas/ImageBitmap.h
+++ b/dom/canvas/ImageBitmap.h
@@ -174,16 +174,18 @@ public:
   MappedDataLength(ImageBitmapFormat aFormat, ErrorResult& aRv);
 
   already_AddRefed<Promise>
   MapDataInto(JSContext* aCx,
               ImageBitmapFormat aFormat,
               const ArrayBufferViewOrArrayBuffer& aBuffer,
               int32_t aOffset, ErrorResult& aRv);
 
+  size_t GetAllocatedSize() const;
+
 protected:
 
   /*
    * The default value of aIsPremultipliedAlpha is TRUE because that the
    * data stored in HTMLImageElement, HTMLVideoElement, HTMLCanvasElement,
    * CanvasRenderingContext2D are alpha-premultiplied in default.
    *
    * Actually, if one HTMLCanvasElement's rendering context is WebGLContext, it
@@ -279,16 +281,20 @@ protected:
    * Set mIsCroppingAreaOutSideOfSourceImage if image bitmap was cropped to the
    * source rectangle so that it contains any transparent black pixels (cropping
    * area is outside of the source image).
    * This is used in mapDataInto() to check if we should reject promise with
    * IndexSizeError.
    */
   bool mIsCroppingAreaOutSideOfSourceImage;
 
+  /*
+   * Whether this object allocated allocated and owns the image data.
+   */
+  bool mAllocatedImageData;
 };
 
 } // namespace dom
 } // namespace mozilla
 
 #endif // mozilla_dom_ImageBitmap_h
 
 

--- a/dom/events/DataTransfer.cpp
+++ b/dom/events/DataTransfer.cpp
@@ -76,16 +76,33 @@ const char DataTransfer::sEffects[8][9] 
 };
 
 // Used for custom clipboard types.
 enum CustomClipboardTypeId {
   eCustomClipboardTypeId_None,
   eCustomClipboardTypeId_String
 };
 
+// The dom.events.dataTransfer.protected.enabled preference controls whether or
+// not the `protected` dataTransfer state is enabled. If the `protected`
+// dataTransfer stae is disabled, then the DataTransfer will be read-only
+// whenever it should be protected, and will not be disconnected after a drag
+// event is completed.
+static bool
+PrefProtected()
+{
+  static bool sInitialized = false;
+  static bool sValue = false;
+  if (!sInitialized) {
+    sInitialized = true;
+    Preferences::AddBoolVarCache(&sValue, "dom.events.dataTransfer.protected.enabled");
+  }
+  return sValue;
+}
+
 static DataTransfer::Mode
 ModeForEvent(EventMessage aEventMessage)
 {
   switch (aEventMessage) {
   case eCut:
   case eCopy:
   case eDragStart:
     // For these events, we want to be able to add data to the data transfer,
@@ -93,17 +110,19 @@ ModeForEvent(EventMessage aEventMessage)
     return DataTransfer::Mode::ReadWrite;
   case eDrop:
   case ePaste:
   case ePasteNoFormatting:
     // For these events we want to be able to read the data which is stored in
     // the DataTransfer, rather than just the type information.
     return DataTransfer::Mode::ReadOnly;
   default:
-    return DataTransfer::Mode::Protected;
+    return PrefProtected()
+      ? DataTransfer::Mode::Protected
+      : DataTransfer::Mode::ReadOnly;
   }
 }
 
 DataTransfer::DataTransfer(nsISupports* aParent, EventMessage aEventMessage,
                            bool aIsExternal, int32_t aClipboardType)
   : mParent(aParent)
   , mDropEffect(nsIDragService::DRAGDROP_ACTION_NONE)
   , mEffectAllowed(nsIDragService::DRAGDROP_ACTION_UNINITIALIZED)
@@ -1272,16 +1291,25 @@ DataTransfer::ConvertFromVariant(nsIVari
 
   // each character is two bytes
   *aLength = str.Length() << 1;
 
   return true;
 }
 
 void
+DataTransfer::Disconnect()
+{
+  SetMode(Mode::Protected);
+  if (PrefProtected()) {
+    ClearAll();
+  }
+}
+
+void
 DataTransfer::ClearAll()
 {
   mItems->ClearAllItems();
 }
 
 uint32_t
 DataTransfer::MozItemCount() const
 {
@@ -1603,10 +1631,20 @@ DataTransfer::FillInExternalCustomTypes(
       rv = variant->SetAsAString(data);
       NS_ENSURE_SUCCESS_VOID(rv);
 
       SetDataWithPrincipal(format, variant, aIndex, aPrincipal);
     }
   } while (type != eCustomClipboardTypeId_None);
 }
 
+void
+DataTransfer::SetMode(DataTransfer::Mode aMode)
+{
+  if (!PrefProtected() && aMode == Mode::Protected) {
+    mMode = Mode::ReadOnly;
+  } else {
+    mMode = aMode;
+  }
+}
+
 } // namespace dom
 } // namespace mozilla

--- a/dom/events/DataTransfer.h
+++ b/dom/events/DataTransfer.h
@@ -224,19 +224,17 @@ public:
   }
 
   // Returns the current "Drag Data Store Mode" of the DataTransfer. This
   // determines what modifications may be performed on the DataTransfer, and
   // what data may be read from it.
   Mode GetMode() const {
     return mMode;
   }
-  void SetMode(Mode aMode) {
-    mMode = aMode;
-  }
+  void SetMode(Mode aMode);
 
   // Helper method. Is true if the DataTransfer's mode is ReadOnly or Protected,
   // which means that the DataTransfer cannot be modified.
   bool IsReadOnly() const {
     return mMode != Mode::ReadWrite;
   }
   // Helper method. Is true if the DataTransfer's mode is Protected, which means
   // that DataTransfer type information may be read, but data may not be.
@@ -267,16 +265,22 @@ public:
   GetTransferable(uint32_t aIndex, nsILoadContext* aLoadContext);
 
   // converts the data in the variant to an nsISupportString if possible or
   // an nsISupports or null otherwise.
   bool ConvertFromVariant(nsIVariant* aVariant,
                           nsISupports** aSupports,
                           uint32_t* aLength) const;
 
+  // Disconnects the DataTransfer from the Drag Data Store. If the
+  // dom.dataTransfer.disconnect pref is enabled, this will clear the
+  // DataTransfer and set it to the `Protected` state, otherwise this method is
+  // a no-op.
+  void Disconnect();
+
   // clears all of the data
   void ClearAll();
 
   // Similar to SetData except also specifies the principal to store.
   // aData may be null when called from CacheExternalDragFormats or
   // CacheExternalClipboardFormats.
   nsresult SetDataWithPrincipal(const nsAString& aFormat,
                                 nsIVariant* aData,

--- a/dom/events/EventNameList.h
+++ b/dom/events/EventNameList.h
@@ -546,16 +546,20 @@ WINDOW_EVENT(languagechange,
              eBasicEventClass)
 // XXXbz Should the onmessage attribute on <body> really not work?  If so, do we
 // need a different macro to flag things like that (IDL, but not content
 // attributes on body/frameset), or is just using EventNameType_None enough?
 WINDOW_EVENT(message,
              eMessage,
              EventNameType_None,
              eBasicEventClass)
+WINDOW_EVENT(messageerror,
+             eMessageError,
+             EventNameType_HTMLBodyOrFramesetOnly,
+             eBasicEventClass)
 WINDOW_EVENT(offline,
              eOffline,
              EventNameType_XUL | EventNameType_HTMLBodyOrFramesetOnly,
              eBasicEventClass)
 WINDOW_EVENT(online,
              eOnline,
              EventNameType_XUL | EventNameType_HTMLBodyOrFramesetOnly,
              eBasicEventClass)

--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -1769,18 +1769,17 @@ EventStateManager::GenerateDragGesture(n
       nsCOMPtr<nsPIDOMWindowOuter> window = docshell->GetWindow();
       if (!window)
         return;
 
       RefPtr<DataTransfer> dataTransfer =
         new DataTransfer(window, eDragStart, false, -1);
       auto protectDataTransfer = MakeScopeExit([&] {
         if (dataTransfer) {
-          dataTransfer->SetMode(DataTransfer::Mode::Protected);
-          dataTransfer->ClearAll();
+          dataTransfer->Disconnect();
         }
       });
 
       nsCOMPtr<nsISelection> selection;
       nsCOMPtr<nsIContent> eventContent, targetContent;
       mCurrentTarget->GetContentForEvent(aEvent, getter_AddRefs(eventContent));
       if (eventContent)
         DetermineDragTargetAndDefaultData(window, eventContent, dataTransfer,

--- a/dom/events/IMEContentObserver.cpp
+++ b/dom/events/IMEContentObserver.cpp
@@ -1371,17 +1371,20 @@ IMEContentObserver::MaybeNotifyIMEOfAdde
 void
 IMEContentObserver::BeginDocumentUpdate()
 {
   MOZ_LOG(sIMECOLog, LogLevel::Debug,
     ("0x%p IMEContentObserver::BeginDocumentUpdate(), "
      "HasAddedNodesDuringDocumentChange()=%s",
      this, ToChar(HasAddedNodesDuringDocumentChange())));
 
-  MOZ_ASSERT(!HasAddedNodesDuringDocumentChange());
+  // If we're not in a nested document update, this will return early,
+  // otherwise, it will handle flusing any changes currently pending before
+  // entering a nested document update.
+  MaybeNotifyIMEOfAddedTextDuringDocumentChange();
 }
 
 void
 IMEContentObserver::EndDocumentUpdate()
 {
   MOZ_LOG(sIMECOLog, LogLevel::Debug,
     ("0x%p IMEContentObserver::EndDocumentUpdate(), "
      "HasAddedNodesDuringDocumentChange()=%s",

--- a/dom/events/test/test_bug508479.html
+++ b/dom/events/test/test_bug508479.html
@@ -69,17 +69,17 @@ function runTests()
   is(gGotNotHandlingDrop, false, "Didn't get drop on unaccepting element (1)");
 
   // reset
   gGotHandlingDrop = false;
   gGotNotHandlingDrop = false;
 
   SpecialPowers.addChromeEventListener("drop", chromeListener, true, false);
   var targetNotHandling = document.getElementById("nothandling_target");
-  fireDrop(targetNotHandling, false, true);
+  fireDrop(targetNotHandling, true, true);
   SpecialPowers.removeChromeEventListener("drop", chromeListener, true);
   ok(chromeGotEvent, "Chrome should have got drop event!");
   is(gGotHandlingDrop, false, "Didn't get drop on accepting element (2)");
   is(gGotNotHandlingDrop, false, "Didn't get drop on unaccepting element (2)");
 
   SimpleTest.finish();
 }
 

--- a/dom/file/Blob.cpp
+++ b/dom/file/Blob.cpp
@@ -287,17 +287,17 @@ Blob::IsMemoryFile() const
 }
 
 void
 Blob::GetInternalStream(nsIInputStream** aStream, ErrorResult& aRv)
 {
   mImpl->GetInternalStream(aStream, aRv);
 }
 
-uint64_t
+size_t
 BindingJSObjectMallocBytes(Blob* aBlob)
 {
   MOZ_ASSERT(aBlob);
   return aBlob->GetAllocationSize();
 }
 
 } // namespace dom
 } // namespace mozilla

--- a/dom/file/Blob.h
+++ b/dom/file/Blob.h
@@ -146,14 +146,14 @@ protected:
   RefPtr<BlobImpl> mImpl;
 
 private:
   nsCOMPtr<nsISupports> mParent;
 };
 
 // Override BindingJSObjectMallocBytes for blobs to tell the JS GC how much
 // memory is held live by the binding object.
-uint64_t BindingJSObjectMallocBytes(Blob* aBlob);
+size_t BindingJSObjectMallocBytes(Blob* aBlob);
 
 } // namespace dom
 } // namespace mozilla
 
 #endif // mozilla_dom_Blob_h

--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -2305,18 +2305,16 @@ ContentChild::ActorDestroy(ActorDestroyR
   }
 
   if (AbnormalShutdown == why) {
     NS_WARNING("shutting down early because of crash!");
     ProcessChild::QuickExit();
   }
 
 #ifndef NS_FREE_PERMANENT_DATA
-  CompositorManagerChild::Shutdown();
-
   // In release builds, there's no point in the content process
   // going through the full XPCOM shutdown path, because it doesn't
   // keep persistent state.
   ProcessChild::QuickExit();
 #else
   if (gFirstIdleTask) {
     gFirstIdleTask->Cancel();
   }

--- a/dom/media/mediasource/test/mochitest.ini
+++ b/dom/media/mediasource/test/mochitest.ini
@@ -154,10 +154,10 @@ skip-if = android_version == '22' # bug 
 skip-if = ((os == "win" && os_version == "5.1") || (toolkit == 'android')) # Not supported on xp and android 2.3
 [test_WaitingOnMissingData.html]
 skip-if = (toolkit == 'android') #timeout android only bug 1101187
 [test_WaitingOnMissingData_mp4.html]
 skip-if = ((os == "win" && os_version == "5.1") || (toolkit == 'android')) # Not supported on xp and android 2.3
 [test_WaitingOnMissingDataEnded_mp4.html]
 skip-if = ((os == "win" && os_version == "5.1") || (toolkit == 'android')) # Not supported on xp and android 2.3
 [test_WaitingToEndedTransition_mp4.html]
-skip-if = ((os == "win" && os_version == "5.1") || (toolkit == 'android')) # Not supported on xp and android 2.3
+skip-if = ((os == "win" && os_version >= "10.0") || (toolkit == 'android')) # Not supported on android 2.3, failing on windows 10
 

--- a/dom/messagechannel/MessagePort.cpp
+++ b/dom/messagechannel/MessagePort.cpp
@@ -132,27 +132,29 @@ private:
       end = MakeUnique<MessagePortTimelineMarker>(
         ProfileTimelineMessagePortOperationType::DeserializeData,
         MarkerTracingType::END);
       timelines->AddMarkerForAllObservedDocShells(start);
       timelines->AddMarkerForAllObservedDocShells(end);
     }
 
     if (NS_WARN_IF(rv.Failed())) {
+      mPort->DispatchError();
       return rv.StealNSResult();
     }
 
     // Create the event
     nsCOMPtr<mozilla::dom::EventTarget> eventTarget =
       do_QueryInterface(mPort->GetOwner());
     RefPtr<MessageEvent> event =
       new MessageEvent(eventTarget, nullptr, nullptr);
 
     Sequence<OwningNonNull<MessagePort>> ports;
     if (!mData->TakeTransferredPortsAsSequence(ports)) {
+      mPort->DispatchError();
       return NS_ERROR_OUT_OF_MEMORY;
     }
 
     event->InitMessageEvent(nullptr, NS_LITERAL_STRING("message"),
                             false /* non-bubbling */,
                             false /* cancelable */, value, EmptyString(),
                             EmptyString(), nullptr, ports);
     event->SetTrusted(true);
@@ -689,17 +691,17 @@ MessagePort::Entangled(nsTArray<ClonedMe
     // only clear after `messages` have gone out of scope.
     mMessagesForTheOtherPort.Clear();
   }
 
   // We must convert the messages into SharedMessagePortMessages to avoid leaks.
   FallibleTArray<RefPtr<SharedMessagePortMessage>> data;
   if (NS_WARN_IF(!SharedMessagePortMessage::FromMessagesToSharedChild(aMessages,
                                                                       data))) {
-    // OOM, we cannot continue.
+    DispatchError();
     return;
   }
 
   // If the next step is to close the port, we do it ignoring the received
   // messages.
   if (oldState == eStateEntanglingForClose) {
     CloseForced();
     return;
@@ -743,17 +745,17 @@ MessagePort::MessagesReceived(nsTArray<C
              mState == eStateDisentangledForClose);
   MOZ_ASSERT(mMessagesForTheOtherPort.IsEmpty());
 
   RemoveDocFromBFCache();
 
   FallibleTArray<RefPtr<SharedMessagePortMessage>> data;
   if (NS_WARN_IF(!SharedMessagePortMessage::FromMessagesToSharedChild(aMessages,
                                                                       data))) {
-    // OOM, We cannot continue.
+    DispatchError();
     return;
   }
 
   mMessages.AppendElements(data);
 
   if (mState == eStateEntangled) {
     Dispatch();
   }
@@ -999,10 +1001,33 @@ MessagePort::RemoveDocFromBFCache()
 }
 
 /* static */ void
 MessagePort::ForceClose(const MessagePortIdentifier& aIdentifier)
 {
   ForceCloseHelper::ForceClose(aIdentifier);
 }
 
+void
+MessagePort::DispatchError()
+{
+  nsCOMPtr<nsIGlobalObject> globalObject = GetParentObject();
+
+  AutoJSAPI jsapi;
+  if (!globalObject || !jsapi.Init(globalObject)) {
+    NS_WARNING("Failed to initialize AutoJSAPI object.");
+    return;
+  }
+
+  RootedDictionary<MessageEventInit> init(jsapi.cx());
+  init.mBubbles = false;
+  init.mCancelable = false;
+
+  RefPtr<Event> event =
+    MessageEvent::Constructor(this, NS_LITERAL_STRING("messageerror"), init);
+  event->SetTrusted(true);
+
+  bool dummy;
+  DispatchEvent(event, &dummy);
+}
+
 } // namespace dom
 } // namespace mozilla

--- a/dom/messagechannel/MessagePort.h
+++ b/dom/messagechannel/MessagePort.h
@@ -69,16 +69,18 @@ public:
   void Start();
 
   void Close();
 
   EventHandlerNonNull* GetOnmessage();
 
   void SetOnmessage(EventHandlerNonNull* aCallback);
 
+  IMPL_EVENT_HANDLER(messageerror)
+
   // Non WebIDL methods
 
   void UnshippedEntangle(MessagePort* aEntangledPort);
 
   void CloneAndDisentangle(MessagePortIdentifier& aIdentifier);
 
   void CloseForced();
 
@@ -142,16 +144,18 @@ private:
                   uint32_t aSequenceID, bool mNeutered, State aState,
                   ErrorResult& aRv);
 
   void ConnectToPBackground();
 
   // Dispatch events from the Message Queue using a nsRunnable.
   void Dispatch();
 
+  void DispatchError();
+
   void StartDisentangling();
   void Disentangle();
 
   void RemoveDocFromBFCache();
 
   void CloseInternal(bool aSoftly);
 
   // This method is meant to keep alive the MessagePort when this object is

--- a/dom/tests/mochitest/general/test_clipboard_events.html
+++ b/dom/tests/mochitest/general/test_clipboard_events.html
@@ -741,14 +741,20 @@ function test_image_dataTransfer() {
   try {
     synthesizeKey("v", {accelKey: 1});
     ok(onpasteCalled, "The paste event listener must have been called");
   } finally {
     document.onpaste = null;
   }
 }
 
-SimpleTest.waitForFocus(doTests);
+SimpleTest.waitForFocus(() => {
+  SpecialPowers.pushPrefEnv({
+    // NOTE: These tests operate under the assumption that the protected mode of
+    // DataTransfer is enabled.
+    "set": [["dom.events.dataTransfer.protected.enabled", true]]
+  }, doTests);
+});
 
 </script>
 </pre>
 </body>
 </html>

--- a/dom/tests/mochitest/general/test_interfaces.js
+++ b/dom/tests/mochitest/general/test_interfaces.js
@@ -869,17 +869,17 @@ var interfaceNamesInGlobalScope =
     {name: "SpecialPowers", xbl: false},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "StereoPannerNode",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "Storage",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "StorageEvent",
 // IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "StorageManager", nightly: true, isSecureContext: true, android: false},
+    {name: "StorageManager", isSecureContext: true, android: false},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "StyleSheet",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "StyleSheetList",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "SubtleCrypto",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "SVGAElement",

--- a/dom/webidl/BroadcastChannel.webidl
+++ b/dom/webidl/BroadcastChannel.webidl
@@ -1,21 +1,22 @@
 /* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * For more information on this interface, please see
- * http://www.whatwg.org/specs/web-apps/current-work/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts
+ * https://html.spec.whatwg.org/#broadcastchannel
  */
 
 [Constructor(DOMString channel),
  Exposed=(Window,Worker)]
 interface BroadcastChannel : EventTarget {
   readonly attribute DOMString name;
 
   [Throws]
   void postMessage(any message);
 
   void close();
 
-           attribute EventHandler onmessage;
+  attribute EventHandler onmessage;
+  attribute EventHandler onmessageerror;
 };

--- a/dom/webidl/DedicatedWorkerGlobalScope.webidl
+++ b/dom/webidl/DedicatedWorkerGlobalScope.webidl
@@ -19,9 +19,10 @@ interface DedicatedWorkerGlobalScope : W
   readonly attribute DOMString name;
 
   [Throws]
   void postMessage(any message, optional sequence<object> transfer = []);
 
   void close();
 
   attribute EventHandler onmessage;
+  attribute EventHandler onmessageerror;
 };

--- a/dom/webidl/EventHandler.webidl
+++ b/dom/webidl/EventHandler.webidl
@@ -142,16 +142,17 @@ interface GlobalEventHandlers {
 [NoInterfaceObject]
 interface WindowEventHandlers {
            attribute EventHandler onafterprint;
            attribute EventHandler onbeforeprint;
            attribute OnBeforeUnloadEventHandler onbeforeunload;
            attribute EventHandler onhashchange;
            attribute EventHandler onlanguagechange;
            attribute EventHandler onmessage;
+           attribute EventHandler onmessageerror;
            attribute EventHandler onoffline;
            attribute EventHandler ononline;
            attribute EventHandler onpagehide;
            attribute EventHandler onpageshow;
            attribute EventHandler onpopstate;
            attribute EventHandler onstorage;
            attribute EventHandler onunload;
 };

--- a/dom/webidl/MessagePort.webidl
+++ b/dom/webidl/MessagePort.webidl
@@ -12,10 +12,11 @@ interface MessagePort : EventTarget {
   [Throws]
   void postMessage(any message, optional sequence<object> transferable = []);
 
   void start();
   void close();
 
   // event handlers
   attribute EventHandler onmessage;
+  attribute EventHandler onmessageerror;
 };
 // MessagePort implements Transferable;

--- a/dom/webidl/Worker.webidl
+++ b/dom/webidl/Worker.webidl
@@ -17,16 +17,17 @@
  Exposed=(Window,DedicatedWorker,SharedWorker,System)]
 interface Worker : EventTarget {
   void terminate();
 
   [Throws]
   void postMessage(any message, optional sequence<object> transfer = []);
 
   attribute EventHandler onmessage;
+  attribute EventHandler onmessageerror;
 };
 
 Worker implements AbstractWorker;
 
 dictionary WorkerOptions {
   // WorkerType type = "classic"; TODO: Bug 1247687
   // RequestCredentials credentials = "omit"; // credentials is only used if type is "module" TODO: Bug 1247687
   DOMString name = "";

--- a/dom/workers/ScriptLoader.cpp
+++ b/dom/workers/ScriptLoader.cpp
@@ -675,17 +675,22 @@ private:
     if (mCanceledMainThread || !mCacheCreator) {
       aRequest->Cancel(NS_ERROR_FAILURE);
       return NS_ERROR_FAILURE;
     }
 
     ScriptLoadInfo& loadInfo = mLoadInfos[aIndex];
 
     nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
-    MOZ_ASSERT(channel == loadInfo.mChannel);
+
+    // Note that importScripts() can redirect.  In theory the main
+    // script could also encounter an internal redirect, but currently
+    // the assert does not allow that.
+    MOZ_ASSERT_IF(mIsMainScript, channel == loadInfo.mChannel);
+    loadInfo.mChannel = channel;
 
     // We synthesize the result code, but its never exposed to content.
     RefPtr<mozilla::dom::InternalResponse> ir =
       new mozilla::dom::InternalResponse(200, NS_LITERAL_CSTRING("OK"));
     ir->SetBody(loadInfo.mCacheReadStream, InternalResponse::UNKNOWN_BODY_SIZE);
 
     // Drop our reference to the stream now that we've passed it along, so it
     // doesn't hang around once the cache is done with it and keep data alive.

--- a/dom/workers/WorkerPrivate.cpp
+++ b/dom/workers/WorkerPrivate.cpp
@@ -724,17 +724,17 @@ public:
       if (NS_WARN_IF(!parent)) {
         return false;
       }
     }
 
     MOZ_ASSERT(parent);
 
     JS::Rooted<JS::Value> messageData(aCx);
-    ErrorResult rv;
+    IgnoredErrorResult rv;
 
     UniquePtr<AbstractTimelineMarker> start;
     UniquePtr<AbstractTimelineMarker> end;
     RefPtr<TimelineConsumers> timelines = TimelineConsumers::Get();
     bool isTimelineRecording = timelines && !timelines->IsEmpty();
 
     if (isTimelineRecording) {
       start = MakeUnique<WorkerTimelineMarker>(aIsMainThread
@@ -750,22 +750,23 @@ public:
         ? ProfileTimelineWorkerOperationType::DeserializeDataOnMainThread
         : ProfileTimelineWorkerOperationType::DeserializeDataOffMainThread,
         MarkerTracingType::END);
       timelines->AddMarkerForAllObservedDocShells(start);
       timelines->AddMarkerForAllObservedDocShells(end);
     }
 
     if (NS_WARN_IF(rv.Failed())) {
-      xpc::Throw(aCx, rv.StealNSResult());
+      DispatchError(aCx, aTarget);
       return false;
     }
 
     Sequence<OwningNonNull<MessagePort>> ports;
     if (!TakeTransferredPortsAsSequence(ports)) {
+      DispatchError(aCx, aTarget);
       return false;
     }
 
     nsCOMPtr<nsIDOMEvent> domEvent;
     RefPtr<MessageEvent> event = new MessageEvent(aTarget, nullptr, nullptr);
     event->InitMessageEvent(nullptr,
                             NS_LITERAL_STRING("message"),
                             false /* non-bubbling */,
@@ -809,16 +810,31 @@ private:
                               !aWorkerPrivate->GetParent());
     }
 
     MOZ_ASSERT(aWorkerPrivate == GetWorkerPrivateFromContext(aCx));
 
     return DispatchDOMEvent(aCx, aWorkerPrivate, aWorkerPrivate->GlobalScope(),
                             false);
   }
+
+  void
+  DispatchError(JSContext* aCx, DOMEventTargetHelper* aTarget)
+  {
+    RootedDictionary<MessageEventInit> init(aCx);
+    init.mBubbles = false;
+    init.mCancelable = false;
+
+    RefPtr<Event> event =
+      MessageEvent::Constructor(aTarget, NS_LITERAL_STRING("messageerror"), init);
+    event->SetTrusted(true);
+
+    bool dummy;
+    aTarget->DispatchEvent(event, &dummy);
+  }
 };
 
 class DebuggerMessageEventRunnable : public WorkerDebuggerRunnable {
   nsString mMessage;
 
 public:
   DebuggerMessageEventRunnable(WorkerPrivate* aWorkerPrivate,
                                const nsAString& aMessage)

--- a/dom/workers/WorkerPrivate.h
+++ b/dom/workers/WorkerPrivate.h
@@ -877,16 +877,17 @@ public:
   {
     return mLoadInfo.mLoadFailedAsyncRunnable.forget();
   }
 
   void
   FlushReportsToSharedWorkers(nsIConsoleReportCollector* aReporter);
 
   IMPL_EVENT_HANDLER(message)
+  IMPL_EVENT_HANDLER(messageerror)
   IMPL_EVENT_HANDLER(error)
 
   // Check whether this worker is a secure context.  For use from the parent
   // thread only; the canonical "is secure context" boolean is stored on the
   // compartment of the worker global.  The only reason we don't
   // AssertIsOnParentThread() here is so we can assert that this value matches
   // the one on the compartment, which has to be done from the worker thread.
   bool IsSecureContext() const

--- a/dom/workers/WorkerScope.h
+++ b/dom/workers/WorkerScope.h
@@ -246,16 +246,17 @@ public:
   PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
               const Sequence<JSObject*>& aTransferable,
               ErrorResult& aRv);
 
   void
   Close(JSContext* aCx);
 
   IMPL_EVENT_HANDLER(message)
+  IMPL_EVENT_HANDLER(messageerror)
 };
 
 class SharedWorkerGlobalScope final : public WorkerGlobalScope
 {
   const nsString mName;
 
   ~SharedWorkerGlobalScope() { }
 
@@ -391,16 +392,17 @@ public:
 
   void
   LeaveEventLoop();
 
   void
   PostMessage(const nsAString& aMessage);
 
   IMPL_EVENT_HANDLER(message)
+  IMPL_EVENT_HANDLER(messageerror)
 
   void
   SetImmediate(Function& aHandler, ErrorResult& aRv);
 
   void
   ReportError(JSContext* aCx, const nsAString& aMessage);
 
   void

--- a/dom/workers/test/navigator_worker.js
+++ b/dom/workers/test/navigator_worker.js
@@ -10,17 +10,17 @@ var supportedProps = [
   "appVersion",
   "platform",
   "product",
   "userAgent",
   "onLine",
   "language",
   "languages",
   "hardwareConcurrency",
-  { name: "storage", nightly: true, isSecureContext: true },
+  { name: "storage", isSecureContext: true },
   "connection",
 ];
 
 self.onmessage = function(event) {
   if (!event || !event.data) {
     return;
   }
 

--- a/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
+++ b/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
@@ -207,17 +207,17 @@ var interfaceNamesInGlobalScope =
     "Response",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "ServiceWorker",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "ServiceWorkerGlobalScope",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "ServiceWorkerRegistration",
 // IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "StorageManager", nightly: true, android: false},
+    {name: "StorageManager", android: false},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "SubtleCrypto",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "TextDecoder",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "TextEncoder",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "URL",

--- a/dom/workers/test/test_worker_interfaces.js
+++ b/dom/workers/test/test_worker_interfaces.js
@@ -193,17 +193,17 @@ var interfaceNamesInGlobalScope =
     "PushSubscriptionOptions",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "Request",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "Response",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "ServiceWorkerRegistration",
 // IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "StorageManager", nightly: true, isSecureContext: true, android: false},
+    {name: "StorageManager", isSecureContext: true, android: false},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "SubtleCrypto",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "TextDecoder",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "TextEncoder",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "XMLHttpRequest",

--- a/gfx/ipc/VsyncBridgeParent.cpp
+++ b/gfx/ipc/VsyncBridgeParent.cpp
@@ -23,17 +23,17 @@ VsyncBridgeParent::Start(Endpoint<PVsync
 
   return parent;
 }
 
 VsyncBridgeParent::VsyncBridgeParent()
  : mOpen(false)
 {
   MOZ_COUNT_CTOR(VsyncBridgeParent);
-  mCompositorThreadRef = CompositorThreadHolder::GetSingleton();
+  mCompositorThreadRef = new CompositorThreadHolderDebug("VsyncBridge");
 }
 
 VsyncBridgeParent::~VsyncBridgeParent()
 {
   MOZ_COUNT_DTOR(VsyncBridgeParent);
 }
 
 void

--- a/gfx/ipc/VsyncBridgeParent.h
+++ b/gfx/ipc/VsyncBridgeParent.h
@@ -33,15 +33,15 @@ private:
   VsyncBridgeParent();
   ~VsyncBridgeParent();
 
   void Open(Endpoint<PVsyncBridgeParent>&& aEndpoint);
   void ShutdownImpl();
 
 private:
   bool mOpen;
-  RefPtr<layers::CompositorThreadHolder> mCompositorThreadRef;
+  RefPtr<layers::CompositorThreadHolderDebug> mCompositorThreadRef;
 };
 
 } // namespace gfx
 } // namespace mozilla
 
 #endif // include_gfx_ipc_VsyncBridgeParent_h

--- a/gfx/layers/d3d11/MLGDeviceD3D11.cpp
+++ b/gfx/layers/d3d11/MLGDeviceD3D11.cpp
@@ -1088,16 +1088,27 @@ MLGDeviceD3D11::InitSamplerStates()
     desc.AddressW = D3D11_TEXTURE_ADDRESS_BORDER;
     memset(desc.BorderColor, 0, sizeof(desc.BorderColor));
     HRESULT hr = mDevice->CreateSamplerState(&desc, getter_AddRefs(mSamplerStates[SamplerMode::LinearClampToZero]));
     if (FAILED(hr)) {
       return Fail("FEATURE_FAILURE_LINEAR_CLAMP_ZERO_SAMPLER",
                   "Could not create linear clamp to zero sampler (%x)", hr);
     }
   }
+  {
+    CD3D11_SAMPLER_DESC desc = CD3D11_SAMPLER_DESC(CD3D11_DEFAULT());
+    desc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
+    desc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
+    desc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
+    HRESULT hr = mDevice->CreateSamplerState(&desc, getter_AddRefs(mSamplerStates[SamplerMode::LinearRepeat]));
+    if (FAILED(hr)) {
+      return Fail("FEATURE_FAILURE_LINEAR_CLAMP_ZERO_SAMPLER",
+                  "Could not create linear clamp to zero sampler (%x)", hr);
+    }
+  }
 
   {
     CD3D11_SAMPLER_DESC desc = CD3D11_SAMPLER_DESC(CD3D11_DEFAULT());
     desc.Filter = D3D11_FILTER_MIN_MAG_MIP_POINT;
     HRESULT hr = mDevice->CreateSamplerState(&desc, getter_AddRefs(mSamplerStates[SamplerMode::Point]));
     if (FAILED(hr)) {
       return Fail("FEATURE_FAILURE_POINT_SAMPLER",
                   "Could not create point sampler (%x)", hr);

--- a/gfx/layers/ipc/CompositorManagerParent.cpp
+++ b/gfx/layers/ipc/CompositorManagerParent.cpp
@@ -31,16 +31,18 @@ CompositorManagerParent::CreateSameProce
     MOZ_ASSERT_UNREACHABLE("Already initialized");
     return nullptr;
   }
 
   // The child is responsible for setting up the IPC channel in the same
   // process case because if we open from the child perspective, we can do it
   // on the main thread and complete before we return the manager handles.
   RefPtr<CompositorManagerParent> parent = new CompositorManagerParent();
+  parent->mCompositorThreadHolder =
+    new CompositorThreadHolderDebug("CompositorManagerSame");
   parent->SetOtherProcessId(base::GetCurrentProcId());
 
   // CompositorManagerParent::Bind would normally add a reference for IPDL but
   // we don't use that in the same process case.
   parent.get()->AddRef();
   sInstance = parent;
   return parent.forget();
 }
@@ -50,16 +52,18 @@ CompositorManagerParent::Create(Endpoint
 {
   MOZ_ASSERT(NS_IsMainThread());
 
   // We are creating a manager for the another process, inside the GPU process
   // (or UI process if it subsumbed the GPU process).
   MOZ_ASSERT(aEndpoint.OtherPid() != base::GetCurrentProcId());
 
   RefPtr<CompositorManagerParent> bridge = new CompositorManagerParent();
+  bridge->mCompositorThreadHolder =
+    new CompositorThreadHolderDebug("CompositorManagerContent");
 
   RefPtr<Runnable> runnable = NewRunnableMethod<Endpoint<PCompositorManagerParent>&&>(
     "CompositorManagerParent::Bind",
     bridge,
     &CompositorManagerParent::Bind,
     Move(aEndpoint));
   CompositorThreadHolder::Loop()->PostTask(runnable.forget());
 }
@@ -100,17 +104,16 @@ CompositorManagerParent::CreateSameProce
     new CompositorBridgeParent(sInstance, aScale, vsyncRate, aOptions,
                                aUseExternalSurfaceSize, aSurfaceSize);
 
   sInstance->mPendingCompositorBridges.AppendElement(bridge);
   return bridge.forget();
 }
 
 CompositorManagerParent::CompositorManagerParent()
-  : mCompositorThreadHolder(CompositorThreadHolder::GetSingleton())
 {
 }
 
 CompositorManagerParent::~CompositorManagerParent()
 {
 }
 
 void

--- a/gfx/layers/ipc/CompositorManagerParent.h
+++ b/gfx/layers/ipc/CompositorManagerParent.h
@@ -13,17 +13,17 @@
 #include "mozilla/RefPtr.h"             // for already_AddRefed
 #include "mozilla/layers/PCompositorManagerParent.h"
 #include "nsTArray.h"                   // for AutoTArray
 
 namespace mozilla {
 namespace layers {
 
 class CompositorBridgeParent;
-class CompositorThreadHolder;
+class CompositorThreadHolderDebug;
 
 class CompositorManagerParent final : public PCompositorManagerParent
 {
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorManagerParent)
 
 public:
   static already_AddRefed<CompositorManagerParent> CreateSameProcess();
   static void Create(Endpoint<PCompositorManagerParent>&& aEndpoint);
@@ -47,17 +47,17 @@ private:
   ~CompositorManagerParent() override;
 
   void Bind(Endpoint<PCompositorManagerParent>&& aEndpoint);
 
   void DeallocPCompositorManagerParent() override;
 
   void DeferredDestroy();
 
-  RefPtr<CompositorThreadHolder> mCompositorThreadHolder;
+  RefPtr<CompositorThreadHolderDebug> mCompositorThreadHolder;
 
   AutoTArray<RefPtr<CompositorBridgeParent>, 1> mPendingCompositorBridges;
 };
 
 } // namespace layers
 } // namespace mozilla
 
 #endif

--- a/gfx/layers/ipc/CompositorThread.cpp
+++ b/gfx/layers/ipc/CompositorThread.cpp
@@ -4,26 +4,56 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "CompositorThread.h"
 #include "MainThreadUtils.h"
 #include "nsThreadUtils.h"
 #include "CompositorBridgeParent.h"
 #include "mozilla/layers/ImageBridgeParent.h"
 #include "mozilla/media/MediaSystemResourceService.h"
+#ifdef MOZ_CRASHREPORTER
+#include "nsExceptionHandler.h"     // for CrashReporter
+#endif
 
 namespace mozilla {
 
 namespace gfx {
 // See VRManagerChild.cpp
 void ReleaseVRManagerParentSingleton();
 } // namespace gfx
 
 namespace layers {
 
+#ifdef MOZ_CRASHREPORTER
+static Atomic<int32_t> sHoldersNextId(0);
+#endif
+
+CompositorThreadHolderDebug::CompositorThreadHolderDebug(const char* aName)
+  : mHolder(CompositorThreadHolder::GetSingleton())
+{
+#ifdef MOZ_CRASHREPORTER
+  if (XRE_IsParentProcess()) {
+    mId.AppendLiteral("gfxCompositorThread:");
+    mId.Append(aName);
+    mId.AppendLiteral(":");
+    mId.AppendInt(++sHoldersNextId);
+    CrashReporter::AnnotateCrashReport(mId, NS_LITERAL_CSTRING("1"));
+  }
+#endif
+}
+
+CompositorThreadHolderDebug::~CompositorThreadHolderDebug()
+{
+#ifdef MOZ_CRASHREPORTER
+  if (XRE_IsParentProcess()) {
+    CrashReporter::AnnotateCrashReport(mId, NS_LITERAL_CSTRING("0"));
+  }
+#endif
+}
+
 static StaticRefPtr<CompositorThreadHolder> sCompositorThreadHolder;
 static bool sFinishedCompositorShutDown = false;
 
 // See ImageBridgeChild.cpp
 void ReleaseImageBridgeParentSingleton();
 
 CompositorThreadHolder* GetCompositorThreadHolder()
 {

--- a/gfx/layers/ipc/CompositorThread.h
+++ b/gfx/layers/ipc/CompositorThread.h
@@ -55,14 +55,30 @@ private:
   base::Thread* const mCompositorThread;
 
   static base::Thread* CreateCompositorThread();
   static void DestroyCompositorThread(base::Thread* aCompositorThread);
 
   friend class CompositorBridgeParent;
 };
 
+class CompositorThreadHolderDebug final
+{
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorThreadHolderDebug)
+
+public:
+  explicit CompositorThreadHolderDebug(const char* aName);
+
+private:
+  ~CompositorThreadHolderDebug();
+
+  RefPtr<CompositorThreadHolder> mHolder;
+#ifdef MOZ_CRASHREPORTER
+  nsAutoCString mId;
+#endif
+};
+
 base::Thread* CompositorThread();
 
 } // namespace layers
 } // namespace mozilla
 
 #endif // mozilla_layers_CompositorThread_h

--- a/gfx/layers/ipc/ImageBridgeParent.cpp
+++ b/gfx/layers/ipc/ImageBridgeParent.cpp
@@ -362,17 +362,19 @@ ImageBridgeParent::GetInstance(ProcessId
   MonitorAutoLock lock(*sImageBridgesLock);
   NS_ASSERTION(sImageBridges.count(aId) == 1, "ImageBridgeParent for the process");
   return sImageBridges[aId];
 }
 
 void
 ImageBridgeParent::OnChannelConnected(int32_t aPid)
 {
-  mCompositorThreadHolder = GetCompositorThreadHolder();
+  mCompositorThreadHolder =
+    new CompositorThreadHolderDebug(IsSameProcess() ? "ImageBridgeSame"
+                                                    : "ImageBridge");
 }
 
 
 bool
 ImageBridgeParent::AllocShmem(size_t aSize,
                       ipc::SharedMemory::SharedMemoryType aType,
                       ipc::Shmem* aShmem)
 {

--- a/gfx/layers/ipc/ImageBridgeParent.h
+++ b/gfx/layers/ipc/ImageBridgeParent.h
@@ -136,15 +136,15 @@ private:
   bool mSetChildThreadPriority;
   bool mClosed;
 
   /**
    * Map of all living ImageBridgeParent instances
    */
   static std::map<base::ProcessId, ImageBridgeParent*> sImageBridges;
 
-  RefPtr<CompositorThreadHolder> mCompositorThreadHolder;
+  RefPtr<CompositorThreadHolderDebug> mCompositorThreadHolder;
 };
 
 } // namespace layers
 } // namespace mozilla
 
 #endif // gfx_layers_ipc_ImageBridgeParent_h_

--- a/gfx/layers/ipc/VideoBridgeParent.cpp
+++ b/gfx/layers/ipc/VideoBridgeParent.cpp
@@ -16,17 +16,17 @@ using namespace mozilla::gfx;
 
 static VideoBridgeParent* sVideoBridgeSingleton;
 
 VideoBridgeParent::VideoBridgeParent()
   : mClosed(false)
 {
   mSelfRef = this;
   sVideoBridgeSingleton = this;
-  mCompositorThreadRef = CompositorThreadHolder::GetSingleton();
+  mCompositorThreadRef = new CompositorThreadHolderDebug("VideoBridge");
 }
 
 VideoBridgeParent::~VideoBridgeParent()
 {
   sVideoBridgeSingleton = nullptr;
 }
 
 /* static */ VideoBridgeParent*

--- a/gfx/layers/ipc/VideoBridgeParent.h
+++ b/gfx/layers/ipc/VideoBridgeParent.h
@@ -7,17 +7,17 @@
 #define gfx_layers_ipc_VideoBridgeParent_h_
 
 #include "mozilla/layers/PVideoBridgeParent.h"
 #include "mozilla/layers/ISurfaceAllocator.h"
 
 namespace mozilla {
 namespace layers {
 
-class CompositorThreadHolder;
+class CompositorThreadHolderDebug;
 
 class VideoBridgeParent final : public PVideoBridgeParent,
                                 public HostIPCAllocator,
                                 public ShmemAllocator
 {
 public:
   VideoBridgeParent();
   ~VideoBridgeParent();
@@ -58,17 +58,17 @@ public:
   void DeallocShmem(ipc::Shmem& aShmem) override;
 
 private:
   void DeallocPVideoBridgeParent() override;
 
   // This keeps us alive until ActorDestroy(), at which point we do a
   // deferred destruction of ourselves.
   RefPtr<VideoBridgeParent> mSelfRef;
-  RefPtr<CompositorThreadHolder> mCompositorThreadRef;
+  RefPtr<CompositorThreadHolderDebug> mCompositorThreadRef;
 
   std::map<uint64_t, PTextureParent*> mTextureMap;
 
   bool mClosed;
 };
 
 } // namespace layers
 } // namespace mozilla

--- a/gfx/layers/mlgpu/ImageLayerMLGPU.cpp
+++ b/gfx/layers/mlgpu/ImageLayerMLGPU.cpp
@@ -72,19 +72,26 @@ ImageLayerMLGPU::IsContentOpaque()
     return gfx::IsOpaque(mHost->CurrentTextureHost()->GetFormat());
   }
   return false;
 }
 
 void
 ImageLayerMLGPU::SetRegionToRender(LayerIntRegion&& aRegion)
 {
-  // See bug 1264142.
-  if (mScaleMode == ScaleMode::STRETCH) {
+  switch (mScaleMode) {
+  case ScaleMode::STRETCH:
+    // See bug 1264142.
     aRegion.AndWith(LayerIntRect(0, 0, mScaleToSize.width, mScaleToSize.height));
+    break;
+  default:
+    // Clamp the visible region to the texture size. (see bug 1396507)
+    MOZ_ASSERT(mScaleMode == ScaleMode::SCALE_NONE);
+    aRegion.AndWith(LayerIntRect(0, 0, mPictureRect.width, mPictureRect.height));
+    break;
   }
   LayerMLGPU::SetRegionToRender(Move(aRegion));
 }
 
 void
 ImageLayerMLGPU::CleanupResources()
 {
   if (mHost) {

--- a/gfx/layers/mlgpu/MLGDevice.cpp
+++ b/gfx/layers/mlgpu/MLGDevice.cpp
@@ -233,31 +233,16 @@ MLGDevice::SetPSTexturesYUV(uint32_t aSl
 }
 
 void
 MLGDevice::SetPSTexture(uint32_t aSlot, TextureSource* aSource)
 {
   SetPSTextures(aSlot, 1, &aSource);
 }
 
-static inline SamplerMode
-FilterToSamplerMode(gfx::SamplingFilter aFilter)
-{
-  switch (aFilter) {
-  case gfx::SamplingFilter::POINT:
-    return SamplerMode::Point;
-  case gfx::SamplingFilter::LINEAR:
-  case gfx::SamplingFilter::GOOD:
-    return SamplerMode::LinearClamp;
-  default:
-    MOZ_ASSERT_UNREACHABLE("Unknown sampler mode");
-    return SamplerMode::LinearClamp;
-  }
-}
-
 void
 MLGDevice::SetSamplerMode(uint32_t aIndex, gfx::SamplingFilter aFilter)
 {
   SetSamplerMode(aIndex, FilterToSamplerMode(aFilter));
 }
 
 bool
 MLGDevice::Fail(const nsCString& aFailureId, const nsCString* aMessage)

--- a/gfx/layers/mlgpu/MLGDeviceTypes.h
+++ b/gfx/layers/mlgpu/MLGDeviceTypes.h
@@ -2,16 +2,17 @@
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_gfx_layers_mlgpu_MLGDeviceTypes_h
 #define mozilla_gfx_layers_mlgpu_MLGDeviceTypes_h
 
 #include "mozilla/TypedEnumBits.h"
+#include "mozilla/gfx/Types.h"
 
 namespace mozilla {
 namespace layers {
 
 enum class MLGUsage
 {
   // GPU read-only, CPU write once on creation and read/write never.
   Immutable,
@@ -42,16 +43,18 @@ enum class MLGBufferType : uint32_t
 };
 
 enum class SamplerMode
 {
   // Linear filter, clamped to border.
   LinearClamp = 0,
   // Linear filter, clamped to transparent pixels.
   LinearClampToZero,
+  // Linear filter, wrap edges.
+  LinearRepeat,
   // Point filter, clamped to border.
   Point,
   MaxModes
 };
 
 enum class MLGBlendState
 {
   Copy = 0,
@@ -99,12 +102,27 @@ enum class MLGRenderTargetFlags : uint32
   ZBuffer = (1 << 0)
 };
 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(MLGRenderTargetFlags);
 
 // NVIDIA drivers crash when we supply too many rects to ClearView - it
 // seems to cause a stack overflow >= 20 rects. We cap to 12 for now.
 static const size_t kMaxClearViewRects = 12;
 
+static inline SamplerMode
+FilterToSamplerMode(gfx::SamplingFilter aFilter)
+{
+  switch (aFilter) {
+  case gfx::SamplingFilter::POINT:
+    return SamplerMode::Point;
+  case gfx::SamplingFilter::LINEAR:
+  case gfx::SamplingFilter::GOOD:
+    return SamplerMode::LinearClamp;
+  default:
+    MOZ_ASSERT_UNREACHABLE("Unknown sampler mode");
+    return SamplerMode::LinearClamp;
+  }
+}
+
 } // namespace layers
 } // namespace mozilla
 
 #endif // mozilla_gfx_layers_mlgpu_MLGDeviceTypes_h