--- a/browser/base/content/aboutNetError-new.xhtml
+++ b/browser/base/content/aboutNetError-new.xhtml
@@ -85,17 +85,17 @@
         <div id="ed_netOffline">&netOffline.longDesc2;</div>
         <div id="ed_netInterrupt">&netInterrupt.longDesc;</div>
         <div id="ed_deniedPortAccess">&deniedPortAccess.longDesc;</div>
         <div id="ed_proxyResolveFailure">&proxyResolveFailure.longDesc;</div>
         <div id="ed_proxyConnectFailure">&proxyConnectFailure.longDesc;</div>
         <div id="ed_contentEncodingError">&contentEncodingError.longDesc;</div>
         <div id="ed_unsafeContentType">&unsafeContentType.longDesc;</div>
         <div id="ed_nssFailure2">&nssFailure2.longDesc2;</div>
-        <div id="ed_nssBadCert">&certerror.introPara1;</div>
+        <div id="ed_nssBadCert">&certerror.introPara2;</div>
         <div id="ed_cspBlocked">&cspBlocked.longDesc;</div>
         <div id="ed_remoteXUL">&remoteXUL.longDesc;</div>
         <div id="ed_corruptedContentErrorv2">&corruptedContentErrorv2.longDesc;</div>
         <div id="ed_sslv3Used">&sslv3Used.longDesc2;</div>
         <div id="ed_inadequateSecurityError">&inadequateSecurityError.longDesc;</div>
         <div id="ed_blockedByPolicy"></div>
         <div id="ed_clockSkewError">&clockSkewError.longDesc;</div>
       </div>

--- a/browser/base/content/test/general/browser.ini
+++ b/browser/base/content/test/general/browser.ini
@@ -472,16 +472,17 @@ support-files =
   file_about_parent.html
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_e10s_switchbrowser.js]
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_e10s_about_process.js]
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_e10s_chrome_process.js]
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
+skip-if = (os == 'linux' && debug) || (os == 'osx' && debug) # Bug 1444565
 [browser_e10s_javascript.js]
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_blockHPKP.js]
 skip-if = verify && !debug
 uses-unsafe-cpows = true
 tags = psm
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_windowactivation.js]

--- a/browser/base/content/test/static/browser_all_files_referenced.js
+++ b/browser/base/content/test/static/browser_all_files_referenced.js
@@ -239,23 +239,33 @@ trackResourcePrefix("app");
 
 function getBaseUriForChromeUri(chromeUri) {
   let chromeFile = chromeUri + "gobbledygooknonexistentfile.reallynothere";
   let uri = Services.io.newURI(chromeFile);
   let fileUri = gChromeReg.convertChromeURL(uri);
   return fileUri.resolve(".");
 }
 
+function trackChromeUri(uri) {
+  gChromeMap.set(getBaseUriForChromeUri(uri), uri);
+}
+
+// formautofill registers resource://formautofill/ and
+// chrome://formautofill/content/ dynamically at runtime.
+// Bug 1480276 is about addressing this without this hard-coding.
+trackResourcePrefix("formautofill");
+trackChromeUri("chrome://formautofill/content/");
+
 function parseManifest(manifestUri) {
   return fetchFile(manifestUri.spec).then(data => {
     for (let line of data.split("\n")) {
       let [type, ...argv] = line.split(/\s+/);
       if (type == "content" || type == "skin" || type == "locale") {
         let chromeUri = `chrome://${argv[0]}/${type}/`;
-        gChromeMap.set(getBaseUriForChromeUri(chromeUri), chromeUri);
+        trackChromeUri(chromeUri);
       } else if (type == "override" || type == "overlay") {
         // Overlays aren't really overrides, but behave the same in
         // that the overlay is only referenced if the original xul
         // file is referenced somewhere.
         let os = "os=" + Services.appinfo.OS;
         if (!argv.some(s => s.startsWith("os=") && s != os)) {
           gOverrideMap.set(Services.io.newURI(argv[1]).specIgnoringRef,
                            Services.io.newURI(argv[0]).specIgnoringRef);
@@ -266,16 +276,45 @@ function parseManifest(manifestUri) {
         trackResourcePrefix(argv[0]);
       } else if (type == "component") {
         gComponentsSet.add(argv[1]);
       }
     }
   });
 }
 
+// If the given URI is a webextension manifest, extract the scripts
+// for any embedded APIs.  Returns the passed in URI if the manifest
+// is not a webextension manifest, null otherwise.
+async function parseJsonManifest(uri) {
+  let raw = await fetchFile(uri.spec);
+  let data;
+  try {
+    data = JSON.parse(raw);
+  } catch (ex) {
+    return uri;
+  }
+
+  // Simplistic test for whether this is a webextension manifest:
+  if (data.manifest_version !== 2) {
+    return uri;
+  }
+
+  if (data.experiment_apis) {
+    for (let api of Object.values(data.experiment_apis)) {
+      if (api.parent && api.parent.script) {
+        let script = uri.resolve(api.parent.script);
+        gReferencesFromCode.set(script, null);
+      }
+    }
+  }
+
+  return null;
+}
+
 function addCodeReference(url, fromURI) {
   let from = convertToCodeURI(fromURI.spec);
 
   // Ignore self references.
   if (url == from)
     return;
 
   let ref;
@@ -541,29 +580,42 @@ add_task(async function checkAllTheFiles
   // test infrastructure because it runs against jarfiles there, and
   // our zipreader APIs are all sync)
   let uris = await generateURIsFromDirTree(appDir, [".css", ".manifest", ".jpg", ".png", ".gif", ".svg",  ".dtd", ".properties"].concat(kCodeExtensions));
 
   // Parse and remove all manifests from the list.
   // NOTE that this must be done before filtering out devtools paths
   // so that all chrome paths can be recorded.
   let manifestURIs = [];
+  let jsonManifests = [];
   uris = uris.filter(uri => {
     let path = uri.pathQueryRef;
     if (path.endsWith(".manifest")) {
       manifestURIs.push(uri);
       return false;
+    } else if (path.endsWith("/manifest.json")) {
+      jsonManifests.push(uri);
+      return false;
     }
 
     return true;
   });
 
   // Wait for all manifest to be parsed
   await throttledMapPromises(manifestURIs, parseManifest);
 
+  // manifest.json is a common name, it is used for WebExtension manifests
+  // but also for other things.  To tell them apart, we have to actually
+  // read the contents.  This will populate gExtensionRoots with all
+  // embedded extension APIs, and return any manifest.json files that aren't
+  // webextensions.
+  let nonWebextManifests = (await Promise.all(jsonManifests.map(parseJsonManifest)))
+                                         .filter(uri => !!uri);
+  uris.push(...nonWebextManifests);
+
   addActorModules();
 
   // We build a list of promises that get resolved when their respective
   // files have loaded and produced no errors.
   let allPromises = [];
 
   for (let uri of uris) {
     let path = uri.pathQueryRef;

--- a/browser/base/content/test/static/browser_misused_characters_in_strings.js
+++ b/browser/base/content/test/static/browser_misused_characters_in_strings.js
@@ -9,17 +9,17 @@
  * the end of the test, there is an assertion that all items have been
  * removed from the whitelist, thus ensuring there are no stale entries. */
 let gWhitelist = [{
     file: "netError.dtd",
     key: "certerror.introPara",
     type: "single-quote"
   }, {
     file: "netError.dtd",
-    key: "certerror.introPara1",
+    key: "certerror.introPara2",
     type: "single-quote"
   }, {
     file: "netError.dtd",
     key: "certerror.expiredCert.whatCanYouDoAboutIt2",
     type: "single-quote"
   }, {
     file: "netError.dtd",
     key: "certerror.whatShouldIDo.badStsCertExplanation1",

--- a/browser/components/extensions/test/browser/browser-common.ini
+++ b/browser/components/extensions/test/browser/browser-common.ini
@@ -213,16 +213,17 @@ skip-if = os == 'mac' # Save as PDF not 
 [browser_ext_tabs_sharingState.js]
 [browser_ext_tabs_cookieStoreId.js]
 [browser_ext_tabs_update.js]
 [browser_ext_tabs_zoom.js]
 [browser_ext_tabs_update_url.js]
 [browser_ext_themes_icons.js]
 [browser_ext_themes_validation.js]
 [browser_ext_url_overrides_newtab.js]
+skip-if = (os == 'linux' && debug) || (os == 'win' && debug) # Bug 1465508
 [browser_ext_user_events.js]
 [browser_ext_webRequest.js]
 [browser_ext_webNavigation_frameId0.js]
 [browser_ext_webNavigation_getFrames.js]
 [browser_ext_webNavigation_onCreatedNavigationTarget.js]
 [browser_ext_webNavigation_onCreatedNavigationTarget_contextmenu.js]
 [browser_ext_webNavigation_onCreatedNavigationTarget_named_window.js]
 [browser_ext_webNavigation_onCreatedNavigationTarget_subframe_window_open.js]

--- a/browser/components/extensions/test/browser/browser_ext_addon_debugging_netmonitor.js
+++ b/browser/components/extensions/test/browser/browser_ext_addon_debugging_netmonitor.js
@@ -1,12 +1,16 @@
 /* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set sts=2 sw=2 et tw=80: */
 "use strict";
 
+// There are shutdown issues for which multiple rejections are left uncaught.
+// See bug 1018184 for resolving these issues.
+PromiseTestUtils.whitelistRejectionsGlobally(/File closed/);
+
 ChromeUtils.defineModuleGetter(this, "BrowserToolboxProcess",
                                "resource://devtools/client/framework/ToolboxProcess.jsm");
 
 async function setupToolboxProcessTest(toolboxProcessScript) {
   // Enable addon debugging.
   await SpecialPowers.pushPrefEnv({
     "set": [
       // Force enabling of addons debugging
@@ -106,27 +110,26 @@ add_task(async function test_addon_debug
                       .filter(filterRequest);
 
       return requests.length > 0;
     });
 
     // Call a function defined in the target extension to make assertions
     // on the network requests collected by the netmonitor panel.
     await jsterm.execute(`testNetworkRequestReceived(${JSON.stringify(requests)});`);
+
+    await toolbox.destroy();
     /* eslint-enable no-undef */
   };
 
   await setupToolboxProcessTest(toolboxProcessScript);
   const browserToolboxProcess = new BrowserToolboxProcess({
     addonID: EXTENSION_ID,
   });
 
+  let onToolboxClose = browserToolboxProcess.once("close");
   await extension.awaitFinish("netmonitor_request_logged");
-
-  let onToolboxClose = browserToolboxProcess.once("close");
-  await browserToolboxProcess.close();
-
   await onToolboxClose;
 
   info("Addon Toolbox closed");
 
   await extension.unload();
 });

--- a/browser/extensions/formautofill/FormAutofillStorage.jsm
+++ b/browser/extensions/formautofill/FormAutofillStorage.jsm
@@ -1785,13 +1785,17 @@ FormAutofillStorage.prototype = {
     }
     return data;
   },
 
   // For test only.
   _saveImmediately() {
     return this._store._save();
   },
+
+  _finalize() {
+    return this._store.finalize();
+  },
 };
 
 // The singleton exposed by this module.
 this.formAutofillStorage = new FormAutofillStorage(
   OS.Path.join(OS.Constants.Path.profileDir, PROFILE_JSON_FILE_NAME));

rename from browser/extensions/formautofill/bootstrap.js
rename to browser/extensions/formautofill/api.js
--- a/browser/extensions/formautofill/bootstrap.js
+++ b/browser/extensions/formautofill/api.js
@@ -1,25 +1,22 @@
 /* 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";
 
-/* exported startup, shutdown, install, uninstall */
+/* globals ExtensionAPI */
 
 const STYLESHEET_URI = "chrome://formautofill/content/formautofill.css";
 const CACHED_STYLESHEETS = new WeakMap();
 
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
-ChromeUtils.defineModuleGetter(this, "AddonManager", "resource://gre/modules/AddonManager.jsm");
-ChromeUtils.defineModuleGetter(this, "AddonManagerPrivate",
-                               "resource://gre/modules/AddonManager.jsm");
 ChromeUtils.defineModuleGetter(this, "FormAutofill",
                                "resource://formautofill/FormAutofill.jsm");
 ChromeUtils.defineModuleGetter(this, "formAutofillParent",
                                "resource://formautofill/FormAutofillParent.jsm");
 
 XPCOMUtils.defineLazyServiceGetter(this, "resProto",
                                    "@mozilla.org/network/protocol;1?name=resource",
                                    "nsISubstitutingProtocolHandler");
@@ -45,23 +42,16 @@ function onMaybeOpenPopup(evt) {
   if (CACHED_STYLESHEETS.has(domWindow)) {
     // This window already has autofill stylesheets.
     return;
   }
 
   insertStyleSheet(domWindow, STYLESHEET_URI);
 }
 
-function addUpgradeListener(instanceID) {
-  AddonManager.addUpgradeListener(instanceID, upgrade => {
-    // don't install the upgrade by doing nothing here.
-    // The upgrade will be installed upon next restart.
-  });
-}
-
 function isAvailable() {
   let availablePref = Services.prefs.getCharPref("extensions.formautofill.available");
   if (availablePref == "on") {
     return true;
   } else if (availablePref == "detect") {
     let locale = Services.locale.getRequestedLocale();
     let region = Services.prefs.getCharPref("browser.search.region", "");
     let supportedCountries = Services.prefs.getCharPref("extensions.formautofill.supportedCountries")
@@ -70,90 +60,86 @@ function isAvailable() {
         Services.locale.isAppLocaleRTL) {
       return false;
     }
     return locale == "en-US" && supportedCountries.includes(region);
   }
   return false;
 }
 
-function startup(data) {
-  // We have to do this before actually determining if we're enabled, since
-  // there are scripts inside of the core browser code that depend on the
-  // FormAutofill JSMs being registered.
-  resProto.setSubstitution(RESOURCE_HOST,
-                           Services.io.newURI("chrome/res/", null, data.resourceURI));
+this.formautofill = class extends ExtensionAPI {
+  onStartup() {
+    // We have to do this before actually determining if we're enabled, since
+    // there are scripts inside of the core browser code that depend on the
+    // FormAutofill JSMs being registered.
+    let uri = Services.io.newURI("chrome/res/", null, this.extension.rootURI);
+    resProto.setSubstitution(RESOURCE_HOST, uri);
+
+    let aomStartup = Cc["@mozilla.org/addons/addon-manager-startup;1"]
+                                 .getService(Ci.amIAddonManagerStartup);
+    const manifestURI = Services.io.newURI("manifest.json", null, this.extension.rootURI);
+    this.chromeHandle = aomStartup.registerChrome(manifestURI, [
+      ["content", "formautofill", "chrome/content/"],
+      ["locale", "formautofill", "en-US", "en-US/locale/en-US/"],
+    ]);
+
+    if (!isAvailable()) {
+      Services.prefs.clearUserPref("dom.forms.autocomplete.formautofill");
+      // reset the sync related prefs incase the feature was previously available
+      // but isn't now.
+      Services.prefs.clearUserPref("services.sync.engine.addresses.available");
+      Services.prefs.clearUserPref("services.sync.engine.creditcards.available");
+      Services.telemetry.scalarSet("formautofill.availability", false);
+      return;
+    }
 
-  if (!isAvailable()) {
-    Services.prefs.clearUserPref("dom.forms.autocomplete.formautofill");
-    // reset the sync related prefs incase the feature was previously available
-    // but isn't now.
-    Services.prefs.clearUserPref("services.sync.engine.addresses.available");
-    Services.prefs.clearUserPref("services.sync.engine.creditcards.available");
-    Services.telemetry.scalarSet("formautofill.availability", false);
-    return;
-  }
+    // This pref is used for web contents to detect the autocomplete feature.
+    // When it's true, "element.autocomplete" will return tokens we currently
+    // support -- otherwise it'll return an empty string.
+    Services.prefs.setBoolPref("dom.forms.autocomplete.formautofill", true);
+    Services.telemetry.scalarSet("formautofill.availability", true);
 
-  if (data.hasOwnProperty("instanceID") && data.instanceID) {
-    if (AddonManagerPrivate.isDBLoaded()) {
-      addUpgradeListener(data.instanceID);
+    // This pref determines whether the "addresses"/"creditcards" sync engine is
+    // available (ie, whether it is shown in any UI etc) - it *does not* determine
+    // whether the engine is actually enabled or not.
+    Services.prefs.setBoolPref("services.sync.engine.addresses.available", true);
+    if (FormAutofill.isAutofillCreditCardsAvailable) {
+      Services.prefs.setBoolPref("services.sync.engine.creditcards.available", true);
     } else {
-      // Wait for the extension database to be loaded so we don't cause its init.
-      Services.obs.addObserver(function xpiDatabaseLoaded() {
-        Services.obs.removeObserver(xpiDatabaseLoaded, "xpi-database-loaded");
-        addUpgradeListener(data.instanceID);
-      }, "xpi-database-loaded");
+      Services.prefs.clearUserPref("services.sync.engine.creditcards.available");
     }
-  } else {
-    throw Error("no instanceID passed to bootstrap startup");
+
+    // Listen for the autocomplete popup message to lazily append our stylesheet related to the popup.
+    Services.mm.addMessageListener("FormAutoComplete:MaybeOpenPopup", onMaybeOpenPopup);
+
+    formAutofillParent.init().catch(Cu.reportError);
+    /* eslint-disable no-unused-vars */
+    Services.ppmm.loadProcessScript("data:,new " + function() {
+      ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
+    }, true);
+    /* eslint-enable no-unused-vars */
+    Services.mm.loadFrameScript("chrome://formautofill/content/FormAutofillFrameScript.js", true, true);
   }
 
-  // This pref is used for web contents to detect the autocomplete feature.
-  // When it's true, "element.autocomplete" will return tokens we currently
-  // support -- otherwise it'll return an empty string.
-  Services.prefs.setBoolPref("dom.forms.autocomplete.formautofill", true);
-  Services.telemetry.scalarSet("formautofill.availability", true);
+  onShutdown() {
+    resProto.setSubstitution(RESOURCE_HOST, null);
 
-  // This pref determines whether the "addresses"/"creditcards" sync engine is
-  // available (ie, whether it is shown in any UI etc) - it *does not* determine
-  // whether the engine is actually enabled or not.
-  Services.prefs.setBoolPref("services.sync.engine.addresses.available", true);
-  if (FormAutofill.isAutofillCreditCardsAvailable) {
-    Services.prefs.setBoolPref("services.sync.engine.creditcards.available", true);
-  } else {
-    Services.prefs.clearUserPref("services.sync.engine.creditcards.available");
-  }
+    this.chromeHandle.destruct();
+    this.chromeHandle = null;
 
-  // Listen for the autocomplete popup message to lazily append our stylesheet related to the popup.
-  Services.mm.addMessageListener("FormAutoComplete:MaybeOpenPopup", onMaybeOpenPopup);
+    Services.mm.removeMessageListener("FormAutoComplete:MaybeOpenPopup", onMaybeOpenPopup);
 
-  formAutofillParent.init().catch(Cu.reportError);
-  /* eslint-disable no-unused-vars */
-  Services.ppmm.loadProcessScript("data:,new " + function() {
-    ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
-  }, true);
-  /* eslint-enable no-unused-vars */
-  Services.mm.loadFrameScript("chrome://formautofill/content/FormAutofillFrameScript.js", true, true);
-}
-
-function shutdown() {
-  resProto.setSubstitution(RESOURCE_HOST, null);
+    let enumerator = Services.wm.getEnumerator("navigator:browser");
+    while (enumerator.hasMoreElements()) {
+      let win = enumerator.getNext();
+      let domWindow = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindow);
+      let cachedStyleSheets = CACHED_STYLESHEETS.get(domWindow);
 
-  Services.mm.removeMessageListener("FormAutoComplete:MaybeOpenPopup", onMaybeOpenPopup);
+      if (!cachedStyleSheets) {
+        continue;
+      }
 
-  let enumerator = Services.wm.getEnumerator("navigator:browser");
-  while (enumerator.hasMoreElements()) {
-    let win = enumerator.getNext();
-    let domWindow = win.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindow);
-    let cachedStyleSheets = CACHED_STYLESHEETS.get(domWindow);
-
-    if (!cachedStyleSheets) {
-      continue;
-    }
-
-    while (cachedStyleSheets.length !== 0) {
-      cachedStyleSheets.pop().remove();
+      while (cachedStyleSheets.length !== 0) {
+        cachedStyleSheets.pop().remove();
+      }
     }
   }
-}
-
-function install() {}
-function uninstall() {}
+};

new file mode 100644
--- /dev/null
+++ b/browser/extensions/formautofill/background.js
@@ -0,0 +1,8 @@
+/* eslint-env webextensions */
+
+"use strict";
+
+browser.runtime.onUpdateAvailable.addListener(details => {
+  // By listening to but ignoring this event, any updates will
+  // be delayed until the next browser restart.
+});

--- a/browser/extensions/formautofill/content/editAddress.xhtml
+++ b/browser/extensions/formautofill/content/editAddress.xhtml
@@ -4,19 +4,19 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <!DOCTYPE html [
   <!ENTITY % globalDTD SYSTEM "chrome://global/locale/global.dtd">
   %globalDTD;
 ]>
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
   <title data-localization="addNewAddressTitle"/>
-  <link rel="stylesheet" href="chrome://formautofill-shared/skin/editDialog.css"/>
-  <link rel="stylesheet" href="chrome://formautofill-shared/skin/editAddress.css"/>
-  <link rel="stylesheet" href="chrome://formautofill/skin/editDialog.css"/>
+  <link rel="stylesheet" href="resource://formautofill/editDialog-shared.css"/>
+  <link rel="stylesheet" href="resource://formautofill/editAddress.css"/>
+  <link rel="stylesheet" href="resource://formautofill/editDialog.css"/>
   <script src="chrome://formautofill/content/l10n.js"></script>
   <script src="chrome://formautofill/content/editDialog.js"></script>
   <script src="chrome://formautofill/content/autofillEditForms.js"></script>
 </head>
 <body dir="&locale.dir;">
   <form id="form" autocomplete="off">
     <div>
       <div id="name-container">

--- a/browser/extensions/formautofill/content/editCreditCard.xhtml
+++ b/browser/extensions/formautofill/content/editCreditCard.xhtml
@@ -4,19 +4,19 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <!DOCTYPE html [
   <!ENTITY % globalDTD SYSTEM "chrome://global/locale/global.dtd">
   %globalDTD;
 ]>
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
   <title data-localization="addNewCreditCardTitle"/>
-  <link rel="stylesheet" href="chrome://formautofill-shared/skin/editDialog.css"/>
-  <link rel="stylesheet" href="chrome://formautofill-shared/skin/editCreditCard.css"/>
-  <link rel="stylesheet" href="chrome://formautofill/skin/editDialog.css"/>
+  <link rel="stylesheet" href="resource://formautofill/editDialog-shared.css"/>
+  <link rel="stylesheet" href="resource://formautofill/editCreditCard.css"/>
+  <link rel="stylesheet" href="resource://formautofill/editDialog.css"/>
   <script src="chrome://formautofill/content/l10n.js"></script>
   <script src="chrome://formautofill/content/editDialog.js"></script>
   <script src="chrome://formautofill/content/autofillEditForms.js"></script>
 </head>
 <body dir="&locale.dir;">
   <form id="form" autocomplete="off">
     <label>
       <span data-localization="cardNumber"/>

--- a/browser/extensions/formautofill/jar.mn
+++ b/browser/extensions/formautofill/jar.mn
@@ -1,18 +1,11 @@
 # 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/.
 
 [features/formautofill@mozilla.org] chrome.jar:
-% resource formautofill %res/
   res/ (*.jsm)
   res/phonenumberutils/ (phonenumberutils/*.jsm)
   res/addressmetadata/ (addressmetadata/*)
-
-% content formautofill %content/
-  content/ (content/*)
+  res/ (skin/shared/*)
 
-% skin formautofill classic/1.0 %skin/linux/ os=LikeUnix
-% skin formautofill classic/1.0 %skin/osx/ os=Darwin
-% skin formautofill classic/1.0 %skin/windows/ os=WINNT
-% skin formautofill-shared classic/1.0 %skin/shared/
-  skin/  (skin/*)
+  content/ (content/*)

rename from browser/extensions/formautofill/install.rdf.in
rename to browser/extensions/formautofill/manifest.json
--- a/browser/extensions/formautofill/install.rdf.in
+++ b/browser/extensions/formautofill/manifest.json
@@ -1,32 +1,26 @@
-<?xml version="1.0"?>
-<!-- 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/. -->
+{
+  "manifest_version": 2,
+  "name": "Form Autofill",
+  "version": "1.0",
 
-#filter substitution
-
-<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
-     xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+  "applications": {
+    "gecko": {
+      "id": "formautofill@mozilla.org"
+    }
+  },
 
-  <Description about="urn:mozilla:install-manifest">
-    <em:id>formautofill@mozilla.org</em:id>
-    <em:version>1.0</em:version>
-    <em:type>2</em:type>
-    <em:bootstrap>true</em:bootstrap>
-    <em:multiprocessCompatible>true</em:multiprocessCompatible>
+  "background": {
+    "scripts": ["background.js"]
+  },
 
-    <!-- Target Application this extension can install into,
-        with minimum and maximum supported versions. -->
-    <em:targetApplication>
-      <Description>
-        <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
-        <em:minVersion>@MOZ_APP_VERSION@</em:minVersion>
-        <em:maxVersion>@MOZ_APP_MAXVERSION@</em:maxVersion>
-      </Description>
-    </em:targetApplication>
-
-    <!-- Front End MetaData -->
-    <em:name>Form Autofill</em:name>
-    <em:description>Autofill forms with saved profiles</em:description>
-  </Description>
-</RDF>
+  "experiment_apis": {
+    "formautofill": {
+      "schema": "schema.json",
+      "parent": {
+        "scopes": ["addon_parent"],
+        "script": "api.js",
+        "events": ["startup"]
+      }
+    }
+  }
+}

--- a/browser/extensions/formautofill/moz.build
+++ b/browser/extensions/formautofill/moz.build
@@ -5,22 +5,37 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEFINES['MOZ_APP_VERSION'] = CONFIG['MOZ_APP_VERSION']
 DEFINES['MOZ_APP_MAXVERSION'] = CONFIG['MOZ_APP_MAXVERSION']
 
 DIRS += ['locales']
 
 FINAL_TARGET_FILES.features['formautofill@mozilla.org'] += [
-  'bootstrap.js'
+  'api.js',
+  'background.js',
+  'manifest.json',
+  'schema.json',
 ]
 
-FINAL_TARGET_PP_FILES.features['formautofill@mozilla.org'] += [
-  'install.rdf.in'
-]
+if CONFIG['OS_ARCH'] == 'Linux':
+    FINAL_TARGET_FILES.features['formautofill@mozilla.org'].chrome.res += [
+        'skin/linux/autocomplete-item.css',
+        'skin/linux/editDialog.css',
+    ]
+elif CONFIG['OS_ARCH'] == 'Darwin':
+    FINAL_TARGET_FILES.features['formautofill@mozilla.org'].chrome.res += [
+        'skin/osx/autocomplete-item.css',
+        'skin/osx/editDialog.css',
+    ]
+elif CONFIG['OS_ARCH'] == 'WINNT':
+    FINAL_TARGET_FILES.features['formautofill@mozilla.org'].chrome.res += [
+        'skin/windows/autocomplete-item.css',
+        'skin/windows/editDialog.css',
+    ]
 
 BROWSER_CHROME_MANIFESTS += ['test/browser/browser.ini']
 
 XPCSHELL_TESTS_MANIFESTS += ['test/unit/xpcshell.ini']
 
 MOCHITEST_MANIFESTS += ['test/mochitest/mochitest.ini']
 
 JAR_MANIFESTS += ['jar.mn']

new file mode 100644
--- /dev/null
+++ b/browser/extensions/formautofill/schema.json
@@ -0,0 +1,1 @@
+[]

rename from browser/extensions/formautofill/skin/shared/autocomplete-item.css
rename to browser/extensions/formautofill/skin/shared/autocomplete-item-shared.css

rename from browser/extensions/formautofill/skin/shared/editDialog.css
rename to browser/extensions/formautofill/skin/shared/editDialog-shared.css

--- a/browser/extensions/formautofill/test/unit/head.js
+++ b/browser/extensions/formautofill/test/unit/head.js
@@ -3,72 +3,95 @@
  */
 
 "use strict";
 
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/ObjectUtils.jsm");
 ChromeUtils.import("resource://gre/modules/FormLikeFactory.jsm");
+ChromeUtils.import("resource://gre/modules/AddonManager.jsm");
+ChromeUtils.import("resource://testing-common/AddonTestUtils.jsm");
+ChromeUtils.import("resource://testing-common/ExtensionXPCShellUtils.jsm");
 ChromeUtils.import("resource://testing-common/FileTestUtils.jsm");
 ChromeUtils.import("resource://testing-common/MockDocument.jsm");
 ChromeUtils.import("resource://testing-common/TestUtils.jsm");
 
 ChromeUtils.defineModuleGetter(this, "DownloadPaths",
                                "resource://gre/modules/DownloadPaths.jsm");
 ChromeUtils.defineModuleGetter(this, "FileUtils",
                                "resource://gre/modules/FileUtils.jsm");
 
-XPCOMUtils.defineLazyServiceGetter(this, "resProto",
-                                   "@mozilla.org/network/protocol;1?name=resource",
-                                   "nsISubstitutingProtocolHandler");
+ChromeUtils.defineModuleGetter(this, "ExtensionParent",
+                               "resource://gre/modules/ExtensionParent.jsm");
 
 do_get_profile();
 
 // ================================================
 // Load mocking/stubbing library, sinon
 // docs: http://sinonjs.org/releases/v2.3.2/
 ChromeUtils.import("resource://gre/modules/Timer.jsm");
 Services.scriptloader.loadSubScript("resource://testing-common/sinon-2.3.2.js", this);
 /* globals sinon */
 // ================================================
 
-// Load our bootstrap extension manifest so we can access our chrome/resource URIs.
 const EXTENSION_ID = "formautofill@mozilla.org";
-let extensionDir = Services.dirsvc.get("GreD", Ci.nsIFile);
-extensionDir.append("browser");
-extensionDir.append("features");
-extensionDir.append(EXTENSION_ID);
-let bootstrapFile = extensionDir.clone();
-bootstrapFile.append("bootstrap.js");
-let bootstrapURI = Services.io.newFileURI(bootstrapFile).spec;
-// If the unpacked extension doesn't exist, use the packed version.
-if (!extensionDir.exists()) {
-  extensionDir = extensionDir.parent;
-  extensionDir.append(EXTENSION_ID + ".xpi");
-  let jarURI = Services.io.newFileURI(extensionDir);
-  bootstrapURI = "jar:" + jarURI.spec + "!/bootstrap.js";
+
+AddonTestUtils.init(this);
+
+async function loadExtension() {
+  AddonTestUtils.createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9.2");
+  await AddonTestUtils.promiseStartupManager();
+
+  let extensionPath = Services.dirsvc.get("GreD", Ci.nsIFile);
+  extensionPath.append("browser");
+  extensionPath.append("features");
+  extensionPath.append(EXTENSION_ID);
+
+  if (!extensionPath.exists()) {
+    extensionPath.leafName = `${EXTENSION_ID}.xpi`;
+  }
+
+  let startupPromise = new Promise(resolve => {
+    const {apiManager} = ExtensionParent;
+    function onReady(event, extension) {
+      if (extension.id == EXTENSION_ID) {
+        apiManager.off("ready", onReady);
+        resolve();
+      }
+    }
+
+    apiManager.on("ready", onReady);
+  });
+
+  await AddonManager.installTemporaryAddon(extensionPath);
+  await startupPromise;
 }
-Components.manager.addBootstrappedManifestLocation(extensionDir);
-
-let resURI = Services.io.newURI("chrome/res/", null, Services.io.newURI(bootstrapURI));
-resProto.setSubstitution("formautofill", resURI);
 
 // Returns a reference to a temporary file that is guaranteed not to exist and
 // is cleaned up later. See FileTestUtils.getTempFile for details.
 function getTempFile(leafName) {
   return FileTestUtils.getTempFile(leafName);
 }
 
 async function initProfileStorage(fileName, records, collectionName = "addresses") {
   let {FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {});
   let path = getTempFile(fileName).path;
   let profileStorage = new FormAutofillStorage(path);
   await profileStorage.initialize();
 
+  // AddonTestUtils inserts its own directory provider that manages TmpD.
+  // It removes that directory at shutdown, which races with shutdown
+  // handing in JSONFile/DeferredTask (which is used by FormAutofillStorage).
+  // Avoid the race by explicitly finalizing any formautofill JSONFile
+  // instances created manually by individual tests when the test finishes.
+  registerCleanupFunction(function finalizeAutofillStorage() {
+    return profileStorage._finalize();
+  });
+
   if (!records || !Array.isArray(records)) {
     return profileStorage;
   }
 
   let onChanged = TestUtils.topicObserved(
     "formautofill-storage-changed",
     (subject, data) =>
       data == "add" &&
@@ -94,19 +117,21 @@ function verifySectionFieldDetails(secti
       let expectedField = expectedSectionInfo[fieldIndex];
       delete field._reason;
       delete field.elementWeakRef;
       Assert.deepEqual(field, expectedField);
     });
   });
 }
 
-function runHeuristicsTest(patterns, fixturePathPrefix) {
-  ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
-  ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+async function runHeuristicsTest(patterns, fixturePathPrefix) {
+  add_task(async function setup() {
+    ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+    ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+  });
 
   patterns.forEach(testPattern => {
     add_task(async function() {
       info("Starting test fixture: " + testPattern.fixturePath);
       let file = do_get_file(fixturePathPrefix + testPattern.fixturePath);
       let doc = MockDocument.createTestDocumentFromFile("http://localhost:8080/test/", file);
 
       let forms = [];
@@ -189,9 +214,11 @@ add_task(async function head_initialize(
   // Clean up after every test.
   registerCleanupFunction(function head_cleanup() {
     Services.prefs.clearUserPref("extensions.formautofill.available");
     Services.prefs.clearUserPref("extensions.formautofill.creditCards.available");
     Services.prefs.clearUserPref("extensions.formautofill.heuristics.enabled");
     Services.prefs.clearUserPref("extensions.formautofill.section.enabled");
     Services.prefs.clearUserPref("dom.forms.autocomplete.formautofill");
   });
+
+  await loadExtension();
 });

--- a/browser/extensions/formautofill/test/unit/test_activeStatus.js
+++ b/browser/extensions/formautofill/test/unit/test_activeStatus.js
@@ -1,15 +1,19 @@
 /*
  * Test for status handling in Form Autofill Parent.
  */
 
 "use strict";
 
-let {FormAutofillParent} = ChromeUtils.import("resource://formautofill/FormAutofillParent.jsm", {});
+let FormAutofillParent;
+
+add_task(async function setup() {
+  ({FormAutofillParent} = ChromeUtils.import("resource://formautofill/FormAutofillParent.jsm", {}));
+});
 
 add_task(async function test_activeStatus_init() {
   let formAutofillParent = new FormAutofillParent();
   sinon.spy(formAutofillParent, "_updateStatus");
 
   // Default status is null before initialization
   Assert.equal(formAutofillParent._active, null);
   Assert.equal(Services.ppmm.initialProcessData.autofillEnabled, undefined);

--- a/browser/extensions/formautofill/test/unit/test_addressDataLoader.js
+++ b/browser/extensions/formautofill/test/unit/test_addressDataLoader.js
@@ -1,27 +1,29 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
-
 const SUPPORT_COUNTRIES_TESTCASES = [
   {
     country: "US",
     properties: ["languages", "alternative_names", "sub_keys", "sub_names"],
   },
   {
     country: "CA",
     properties: ["languages", "name", "sub_keys", "sub_names"],
   },
   {
     country: "DE",
     properties: ["name"],
   },
 ];
 
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+});
+
 add_task(async function test_initalState() {
   // addressData should not exist
   Assert.equal(AddressDataLoader._addressData, undefined);
   // Verify _dataLoaded state
   Assert.equal(AddressDataLoader._dataLoaded.country, false);
   Assert.equal(AddressDataLoader._dataLoaded.level1.size, 0);
 });
 

--- a/browser/extensions/formautofill/test/unit/test_autofillFormFields.js
+++ b/browser/extensions/formautofill/test/unit/test_autofillFormFields.js
@@ -1,17 +1,20 @@
 /*
  * Test for form auto fill content helper fill all inputs function.
  */
 /* eslint-disable mozilla/no-arbitrary-setTimeout */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
-let {MasterPassword} = ChromeUtils.import("resource://formautofill/MasterPassword.jsm", {});
+let MasterPassword;
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+  ({MasterPassword} = ChromeUtils.import("resource://formautofill/MasterPassword.jsm", {}));
+});
 
 const TESTCASES = [
   {
     description: "Form without autocomplete property",
     document: `<form><input id="given-name"><input id="family-name">
                <input id="street-addr"><input id="city"><select id="country"></select>
                <input id='email'><input id="tel"></form>`,
     focusedInputId: "given-name",

--- a/browser/extensions/formautofill/test/unit/test_collectFormFields.js
+++ b/browser/extensions/formautofill/test/unit/test_collectFormFields.js
@@ -1,15 +1,17 @@
 /*
  * Test for form auto fill content helper collectFormFields functions.
  */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+});
 
 const TESTCASES = [
   {
     description: "Form without autocomplete property",
     document: `<form><input id="given-name"><input id="family-name">
                <input id="street-addr"><input id="city"><select id="country"></select>
                <input id='email'><input id="phone"></form>`,
     sections: [

--- a/browser/extensions/formautofill/test/unit/test_createRecords.js
+++ b/browser/extensions/formautofill/test/unit/test_createRecords.js
@@ -1,15 +1,17 @@
 /*
  * Test for the normalization of records created by FormAutofillHandler.
  */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+add_task(async function seutp() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+});
 
 const TESTCASES = [
   {
     description: "Don't contain a field whose length of value is greater than 200",
     document: `<form>
                 <input id="given-name" autocomplete="given-name">
                 <input id="organization" autocomplete="organization">
                 <input id="address-level1" autocomplete="address-level1">

--- a/browser/extensions/formautofill/test/unit/test_creditCardRecords.js
+++ b/browser/extensions/formautofill/test/unit/test_creditCardRecords.js
@@ -1,19 +1,23 @@
 /**
  * Tests FormAutofillStorage object with creditCards records.
  */
 
 "use strict";
 
-const {FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {});
 ChromeUtils.defineModuleGetter(this, "Preferences",
                                "resource://gre/modules/Preferences.jsm");
 ChromeUtils.import("resource://gre/modules/CreditCard.jsm");
 
+let FormAutofillStorage;
+add_task(async function setup() {
+  ({FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {}));
+});
+
 const TEST_STORE_FILE_NAME = "test-credit-card.json";
 const COLLECTION_NAME = "creditCards";
 
 const TEST_CREDIT_CARD_1 = {
   "cc-name": "John Doe",
   "cc-number": "4929001587121045",
   "cc-exp-month": 4,
   "cc-exp-year": 2017,

--- a/browser/extensions/formautofill/test/unit/test_extractLabelStrings.js
+++ b/browser/extensions/formautofill/test/unit/test_extractLabelStrings.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+});
 
 const TESTCASES = [
   {
     description: "A label element contains one input element.",
     document: `<label id="typeA"> label type A
                  <!-- This comment should not be extracted. -->
                  <input type="text">
                  <script>FOO</script>

--- a/browser/extensions/formautofill/test/unit/test_findLabelElements.js
+++ b/browser/extensions/formautofill/test/unit/test_findLabelElements.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+});
 
 const TESTCASES = [
   {
     description: "Input contains in a label element.",
     document: `<form>
                  <label id="labelA"> label type A
                    <input id="typeA" type="text">
                  </label>

--- a/browser/extensions/formautofill/test/unit/test_getAdaptedProfiles.js
+++ b/browser/extensions/formautofill/test/unit/test_getAdaptedProfiles.js
@@ -1,15 +1,17 @@
 /*
  * Test for form auto fill content helper fill all inputs function.
  */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHandler.jsm");
+});
 
 const DEFAULT_ADDRESS_RECORD = {
   "guid": "123",
   "street-address": "2 Harrison St\nline2\nline3",
   "address-line1": "2 Harrison St",
   "address-line2": "line2",
   "address-line3": "line3",
   "address-level1": "CA",

--- a/browser/extensions/formautofill/test/unit/test_getCategoriesFromFieldNames.js
+++ b/browser/extensions/formautofill/test/unit/test_getCategoriesFromFieldNames.js
@@ -1,12 +1,14 @@
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+});
 
 add_task(async function test_isAddressField_isCreditCardField() {
   const TEST_CASES = {
     "given-name": {
       isAddressField: true,
       isCreditCardField: false,
     },
     "organization": {

--- a/browser/extensions/formautofill/test/unit/test_getFormInputDetails.js
+++ b/browser/extensions/formautofill/test/unit/test_getFormInputDetails.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
+});
 
 const TESTCASES = [
   {
     description: "Form containing 5 fields with autocomplete attribute.",
     document: `<form id="form1">
                  <input id="street-addr" autocomplete="street-address">
                  <input id="city" autocomplete="address-level2">
                  <select id="country" autocomplete="country"></select>

--- a/browser/extensions/formautofill/test/unit/test_getInfo.js
+++ b/browser/extensions/formautofill/test/unit/test_getInfo.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillHeuristics.jsm");
+});
 
 const TESTCASES = [
   {
     description: "Input element in a label element",
     document: `<form>
                  <label> E-Mail
                    <input id="targetElement" type="text">
                  </label>

--- a/browser/extensions/formautofill/test/unit/test_getRecords.js
+++ b/browser/extensions/formautofill/test/unit/test_getRecords.js
@@ -1,18 +1,22 @@
 /*
  * Test for make sure getRecords can retrieve right collection from storage.
  */
 
 "use strict";
 
-let {FormAutofillParent} = ChromeUtils.import("resource://formautofill/FormAutofillParent.jsm", {});
-ChromeUtils.import("resource://formautofill/MasterPassword.jsm");
 ChromeUtils.import("resource://gre/modules/CreditCard.jsm");
 
+let FormAutofillParent;
+add_task(async function setup() {
+  ({FormAutofillParent} = ChromeUtils.import("resource://formautofill/FormAutofillParent.jsm", {}));
+  ChromeUtils.import("resource://formautofill/MasterPassword.jsm");
+});
+
 const TEST_ADDRESS_1 = {
   "given-name": "Timothy",
   "additional-name": "John",
   "family-name": "Berners-Lee",
   organization: "World Wide Web Consortium",
   "street-address": "32 Vassar Street\nMIT Room 32-G524",
   "address-level2": "Cambridge",
   "address-level1": "MA",

--- a/browser/extensions/formautofill/test/unit/test_isAvailable.js
+++ b/browser/extensions/formautofill/test/unit/test_isAvailable.js
@@ -1,32 +1,37 @@
 /**
  * Test enabling the feature in specific locales and regions.
  */
 
 "use strict";
 
-// Load bootstrap.js into a sandbox to be able to test `isAvailable`
-let sandbox = {};
-Services.scriptloader.loadSubScript(bootstrapURI, sandbox, "utf-8");
-info("bootstrapURI: " + bootstrapURI);
+const DOM_ENABLED_PREF = "dom.forms.autocomplete.formautofill";
 
 add_task(async function test_defaultTestEnvironment() {
-  Assert.ok(sandbox.isAvailable());
+  Assert.ok(Services.prefs.getBoolPref(DOM_ENABLED_PREF));
 });
 
 add_task(async function test_unsupportedRegion() {
   Services.prefs.setCharPref("extensions.formautofill.available", "detect");
   Services.prefs.setCharPref("browser.search.region", "ZZ");
   registerCleanupFunction(function cleanupRegion() {
     Services.prefs.clearUserPref("browser.search.region");
   });
-  Assert.ok(!sandbox.isAvailable());
+
+  let addon = await AddonManager.getAddonByID(EXTENSION_ID);
+  await addon.reload();
+
+  Assert.ok(!Services.prefs.getBoolPref(DOM_ENABLED_PREF));
 });
 
 add_task(async function test_supportedRegion() {
   Services.prefs.setCharPref("extensions.formautofill.available", "detect");
   Services.prefs.setCharPref("browser.search.region", "US");
   registerCleanupFunction(function cleanupRegion() {
     Services.prefs.clearUserPref("browser.search.region");
   });
-  Assert.ok(sandbox.isAvailable());
+
+  let addon = await AddonManager.getAddonByID(EXTENSION_ID);
+  await addon.reload();
+
+  Assert.ok(Services.prefs.getBoolPref(DOM_ENABLED_PREF));
 });

--- a/browser/extensions/formautofill/test/unit/test_isCJKName.js
+++ b/browser/extensions/formautofill/test/unit/test_isCJKName.js
@@ -1,15 +1,17 @@
 /**
  * Tests the "isCJKName" function of FormAutofillNameUtils object.
  */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillNameUtils.jsm");
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillNameUtils.jsm");
+});
 
 // Test cases is initially copied from
 // https://cs.chromium.org/chromium/src/components/autofill/core/browser/autofill_data_util_unittest.cc
 const TESTCASES = [
   {
     // Non-CJK language with only ASCII characters.
     fullName: "Homer Jay Simpson",
     expectedResult: false,

--- a/browser/extensions/formautofill/test/unit/test_isFieldEligibleForAutofill.js
+++ b/browser/extensions/formautofill/test/unit/test_isFieldEligibleForAutofill.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+add_task(async function seutp() {
+  ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+});
 
 const TESTCASES = [
   {
     document: `<input id="targetElement" type="text">`,
     fieldId: "targetElement",
     expectedResult: true,
   },
   {

--- a/browser/extensions/formautofill/test/unit/test_markAsAutofillField.js
+++ b/browser/extensions/formautofill/test/unit/test_markAsAutofillField.js
@@ -1,12 +1,10 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
-
 const TESTCASES = [
   {
     description: "Form containing 8 fields with autocomplete attribute.",
     document: `<form>
                  <input id="given-name" autocomplete="given-name">
                  <input id="additional-name" autocomplete="additional-name">
                  <input id="family-name" autocomplete="family-name">
                  <input id="street-addr" autocomplete="street-address">
@@ -56,19 +54,24 @@ const TESTCASES = [
       "country",
       "email",
       "tel",
     ],
   },
 ];
 
 let markedFieldId = [];
-FormAutofillContent._markAsAutofillField = function(field) {
-  markedFieldId.push(field.id);
-};
+
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
+
+  FormAutofillContent._markAsAutofillField = function(field) {
+    markedFieldId.push(field.id);
+  };
+});
 
 TESTCASES.forEach(testcase => {
   add_task(async function() {
     info("Starting testcase: " + testcase.description);
 
     markedFieldId = [];
 
     let doc = MockDocument.createTestDocument(

--- a/browser/extensions/formautofill/test/unit/test_masterPassword.js
+++ b/browser/extensions/formautofill/test/unit/test_masterPassword.js
@@ -1,16 +1,20 @@
 /**
  * Tests of MasterPassword.jsm
  */
 
 "use strict";
 const {MockRegistrar} =
   ChromeUtils.import("resource://testing-common/MockRegistrar.jsm", {});
-let {MasterPassword} = ChromeUtils.import("resource://formautofill/MasterPassword.jsm", {});
+
+let MasterPassword;
+add_task(async function setup() {
+  ({MasterPassword} = ChromeUtils.import("resource://formautofill/MasterPassword.jsm", {}));
+});
 
 const TESTCASES = [{
   description: "With master password set",
   masterPassword: "fakemp",
   mpEnabled: true,
 },
 {
   description: "Without master password set",
@@ -62,20 +66,20 @@ do_get_profile();
 let windowWatcherCID =
   MockRegistrar.register("@mozilla.org/embedcomp/window-watcher;1",
                          gWindowWatcher);
 registerCleanupFunction(() => {
   MockRegistrar.unregister(windowWatcherCID);
 });
 
 TESTCASES.forEach(testcase => {
-  let token = MasterPassword._token;
-
   add_task(async function test_encrypt_decrypt() {
     info("Starting testcase: " + testcase.description);
+
+    let token = MasterPassword._token;
     token.initPassword(testcase.masterPassword);
 
     // Test only: Force the token login without asking for master password
     token.login(/* force */ false);
     Assert.equal(testcase.mpEnabled, token.isLoggedIn(), "Token should now be logged into");
     Assert.equal(MasterPassword.isEnabled, testcase.mpEnabled);
 
     let testText = "test string";

--- a/browser/extensions/formautofill/test/unit/test_migrateRecords.js
+++ b/browser/extensions/formautofill/test/unit/test_migrateRecords.js
@@ -1,15 +1,19 @@
 /**
  * Tests the migration algorithm in profileStorage.
  */
 
 "use strict";
 
-const {FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {});
+let FormAutofillStorage;
+
+add_task(async function setup() {
+  ({FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {}));
+});
 
 const TEST_STORE_FILE_NAME = "test-profile.json";
 
 const ADDRESS_SCHEMA_VERSION = 1;
 const CREDIT_CARD_SCHEMA_VERSION = 1;
 
 const ADDRESS_TESTCASES = [
   {

--- a/browser/extensions/formautofill/test/unit/test_nameUtils.js
+++ b/browser/extensions/formautofill/test/unit/test_nameUtils.js
@@ -1,15 +1,17 @@
 /**
  * Tests FormAutofillNameUtils object.
  */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillNameUtils.jsm");
+add_task(async function() {
+  ChromeUtils.import("resource://formautofill/FormAutofillNameUtils.jsm");
+});
 
 // Test cases initially copied from
 // https://cs.chromium.org/chromium/src/components/autofill/core/browser/autofill_data_util_unittest.cc
 const TESTCASES = [
   {
     description: "Full name including given, middle and family names",
     fullName: "Homer Jay Simpson",
     nameParts: {

--- a/browser/extensions/formautofill/test/unit/test_onFormSubmitted.js
+++ b/browser/extensions/formautofill/test/unit/test_onFormSubmitted.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillContent.jsm");
+});
 
 const MOCK_DOC = MockDocument.createTestDocument("http://localhost:8080/test/",
                    `<form id="form1">
                       <input id="street-addr" autocomplete="street-address">
                       <select id="address-level1" autocomplete="address-level1">
                         <option value=""></option>
                         <option value="AL">Alabama</option>
                         <option value="AK">Alaska</option>

--- a/browser/extensions/formautofill/test/unit/test_parseAddressFormat.js
+++ b/browser/extensions/formautofill/test/unit/test_parseAddressFormat.js
@@ -1,11 +1,13 @@
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+});
 
 add_task(async function test_parseAddressFormat() {
   const TEST_CASES = [
     {
       fmt: "%N%n%O%n%A%n%C, %S %Z", // US
       parsed: [
         {fieldId: "name", newLine: true},
         {fieldId: "organization", newLine: true},

--- a/browser/extensions/formautofill/test/unit/test_phoneNumber.js
+++ b/browser/extensions/formautofill/test/unit/test_phoneNumber.js
@@ -1,16 +1,18 @@
 /**
  * Tests PhoneNumber.jsm and PhoneNumberNormalizer.jsm.
  */
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/phonenumberutils/PhoneNumber.jsm");
-ChromeUtils.import("resource://formautofill/phonenumberutils/PhoneNumberNormalizer.jsm");
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/phonenumberutils/PhoneNumber.jsm");
+  ChromeUtils.import("resource://formautofill/phonenumberutils/PhoneNumberNormalizer.jsm");
+});
 
 function IsPlain(dial, expected) {
   let result = PhoneNumber.IsPlain(dial);
   Assert.equal(result, expected);
 }
 
 function Normalize(dial, expected) {
   let result = PhoneNumberNormalizer.Normalize(dial);

--- a/browser/extensions/formautofill/test/unit/test_profileAutocompleteResult.js
+++ b/browser/extensions/formautofill/test/unit/test_profileAutocompleteResult.js
@@ -1,13 +1,15 @@
 "use strict";
 
 /* global AddressResult, CreditCardResult */
-// eslint-disable-next-line no-unused-vars
-ChromeUtils.import("resource://formautofill/ProfileAutoCompleteResult.jsm");
+add_task(async function setup() {
+  // eslint-disable-next-line no-unused-vars
+  ChromeUtils.import("resource://formautofill/ProfileAutoCompleteResult.jsm");
+});
 
 let matchingProfiles = [{
   guid: "test-guid-1",
   "given-name": "Timothy",
   "family-name": "Berners-Lee",
   name: "Timothy Berners-Lee",
   organization: "Sesame Street",
   "street-address": "123 Sesame Street.",
@@ -336,25 +338,25 @@ let creditCardTestCases = [{
   fieldName: "",
   expected: {
     searchResult: Ci.nsIAutoCompleteResult.RESULT_FAILURE,
     defaultIndex: 0,
     items: [],
   },
 }];
 
-let testSets = [{
-  collectionConstructor: AddressResult,
-  testCases: addressTestCases,
-}, {
-  collectionConstructor: CreditCardResult,
-  testCases: creditCardTestCases,
-}];
+add_task(async function test_all_patterns() {
+  let testSets = [{
+    collectionConstructor: AddressResult,
+    testCases: addressTestCases,
+  }, {
+    collectionConstructor: CreditCardResult,
+    testCases: creditCardTestCases,
+  }];
 
-add_task(async function test_all_patterns() {
   testSets.forEach(({collectionConstructor, testCases}) => {
     testCases.forEach(testCase => {
       info("Starting testcase: " + testCase.description);
       let actual = new collectionConstructor(testCase.searchString,
                                              testCase.fieldName,
                                              testCase.allFieldNames,
                                              testCase.matchingProfiles,
                                              testCase.options);

--- a/browser/extensions/formautofill/test/unit/test_savedFieldNames.js
+++ b/browser/extensions/formautofill/test/unit/test_savedFieldNames.js
@@ -1,15 +1,19 @@
 /*
  * Test for keeping the valid fields information in initialProcessData.
  */
 
 "use strict";
 
-let {FormAutofillParent} = ChromeUtils.import("resource://formautofill/FormAutofillParent.jsm", {});
+let FormAutofillParent;
+
+add_task(async function setup() {
+  ({FormAutofillParent} = ChromeUtils.import("resource://formautofill/FormAutofillParent.jsm", {}));
+});
 
 add_task(async function test_profileSavedFieldNames_init() {
   let formAutofillParent = new FormAutofillParent();
   sinon.stub(formAutofillParent, "_updateSavedFieldNames");
 
   await formAutofillParent.init();
   await formAutofillParent.formAutofillStorage.initialize();
   Assert.equal(formAutofillParent._updateSavedFieldNames.called, true);

--- a/browser/extensions/formautofill/test/unit/test_storage_remove.js
+++ b/browser/extensions/formautofill/test/unit/test_storage_remove.js
@@ -1,15 +1,18 @@
 /**
  * Tests removing all address/creditcard records.
  */
 
 "use strict";
 
-const {FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {});
+let FormAutofillStorage;
+add_task(async function setup() {
+  ({FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {}));
+});
 
 const TEST_STORE_FILE_NAME = "test-tombstones.json";
 
 const TEST_ADDRESS_1 = {
   "given-name": "Timothy",
   "additional-name": "John",
   "family-name": "Berners-Lee",
   organization: "World Wide Web Consortium",

--- a/browser/extensions/formautofill/test/unit/test_storage_tombstones.js
+++ b/browser/extensions/formautofill/test/unit/test_storage_tombstones.js
@@ -1,15 +1,18 @@
 /**
  * Tests tombstones in address/creditcard records.
  */
 
 "use strict";
 
-const {FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {});
+let FormAutofillStorage;
+add_task(async function setup() {
+  ({FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {}));
+});
 
 const TEST_STORE_FILE_NAME = "test-tombstones.json";
 
 const TEST_ADDRESS_1 = {
   "given-name": "Timothy",
   "additional-name": "John",
   "family-name": "Berners-Lee",
   organization: "World Wide Web Consortium",

--- a/browser/extensions/formautofill/test/unit/test_sync.js
+++ b/browser/extensions/formautofill/test/unit/test_sync.js
@@ -8,18 +8,21 @@
 /* import-globals-from ../../../../../services/sync/tests/unit/head_http_server.js */
 
 "use strict";
 
 ChromeUtils.import("resource://services-sync/service.js");
 ChromeUtils.import("resource://services-sync/constants.js");
 ChromeUtils.import("resource://testing-common/services/sync/utils.js");
 
-let {sanitizeStorageObject, AutofillRecord, AddressesEngine} =
-  ChromeUtils.import("resource://formautofill/FormAutofillSync.jsm", {});
+let sanitizeStorageObject, AutofillRecord, AddressesEngine;
+add_task(async function() {
+  ({sanitizeStorageObject, AutofillRecord, AddressesEngine} =
+    ChromeUtils.import("resource://formautofill/FormAutofillSync.jsm", {}));
+});
 
 
 Services.prefs.setCharPref("extensions.formautofill.loglevel", "Trace");
 initTestLogging("Trace");
 
 const TEST_STORE_FILE_NAME = "test-profile.json";
 
 const TEST_PROFILE_1 = {

--- a/browser/extensions/formautofill/test/unit/test_toOneLineAddress.js
+++ b/browser/extensions/formautofill/test/unit/test_toOneLineAddress.js
@@ -1,12 +1,14 @@
 
 "use strict";
 
-ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+add_task(async function setup() {
+  ChromeUtils.import("resource://formautofill/FormAutofillUtils.jsm");
+});
 
 add_task(async function test_getCategoriesFromFieldNames() {
   const TEST_CASES = [
     {
       strings: ["A", "B", "C", "D"],
       expectedValue: "A B C D",
     },
     {

--- a/browser/extensions/formautofill/test/unit/test_transformFields.js
+++ b/browser/extensions/formautofill/test/unit/test_transformFields.js
@@ -1,15 +1,18 @@
 /**
  * Tests the transform algorithm in profileStorage.
  */
 
 "use strict";
 
-const {FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {});
+let FormAutofillStorage;
+add_task(async function setup() {
+  ({FormAutofillStorage} = ChromeUtils.import("resource://formautofill/FormAutofillStorage.jsm", {}));
+});
 
 const TEST_STORE_FILE_NAME = "test-profile.json";
 
 const ADDRESS_COMPUTE_TESTCASES = [
   // Name
   {
     description: "Has split names",
     address: {
@@ -896,16 +899,18 @@ add_task(async function test_computeAddr
     info("Verify testcase: " + testcase.description);
 
     let guid = profileStorage.addresses.add(testcase.address);
     let address = profileStorage.addresses.get(guid);
     do_check_record_matches(testcase.expectedResult, address);
 
     profileStorage.addresses.remove(guid);
   });
+
+  await profileStorage._finalize();
 });
 
 add_task(async function test_normalizeAddressFields() {
   let path = getTempFile(TEST_STORE_FILE_NAME).path;
 
   let profileStorage = new FormAutofillStorage(path);
   await profileStorage.initialize();
 
@@ -913,16 +918,18 @@ add_task(async function test_normalizeAd
     info("Verify testcase: " + testcase.description);
 
     let guid = profileStorage.addresses.add(testcase.address);
     let address = profileStorage.addresses.get(guid);
     do_check_record_matches(testcase.expectedResult, address);
 
     profileStorage.addresses.remove(guid);
   });
+
+  await profileStorage._finalize();
 });
 
 add_task(async function test_computeCreditCardFields() {
   let path = getTempFile(TEST_STORE_FILE_NAME).path;
 
   let profileStorage = new FormAutofillStorage(path);
   await profileStorage.initialize();
 
@@ -930,16 +937,18 @@ add_task(async function test_computeCred
     info("Verify testcase: " + testcase.description);
 
     let guid = profileStorage.creditCards.add(testcase.creditCard);
     let creditCard = profileStorage.creditCards.get(guid);
     do_check_record_matches(testcase.expectedResult, creditCard);
 
     profileStorage.creditCards.remove(guid);
   });
+
+  await profileStorage._finalize();
 });
 
 add_task(async function test_normalizeCreditCardFields() {
   let path = getTempFile(TEST_STORE_FILE_NAME).path;
 
   let profileStorage = new FormAutofillStorage(path);
   await profileStorage.initialize();
 
@@ -947,9 +956,11 @@ add_task(async function test_normalizeCr
     info("Verify testcase: " + testcase.description);
 
     let guid = profileStorage.creditCards.add(testcase.creditCard);
     let creditCard = profileStorage.creditCards.get(guid, {rawData: true});
     do_check_record_matches(testcase.expectedResult, creditCard);
 
     profileStorage.creditCards.remove(guid);
   });
+
+  await profileStorage._finalize();
 });

--- a/browser/locales/en-US/chrome/overrides/netError.dtd
+++ b/browser/locales/en-US/chrome/overrides/netError.dtd
@@ -145,21 +145,21 @@
 <ul>
   <li>The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.</li>
   <li>Please contact the website owners to inform them of this problem.</li>
 </ul>
 ">
 
 <!ENTITY certerror.longpagetitle1 "Your connection is not secure">
 <!ENTITY certerror.longpagetitle2 "Warning: Potential Security Risk Ahead">
-<!-- Localization note (certerror.introPara, certerror.introPara1) - The text content of the span tag
+<!-- Localization note (certerror.introPara, certerror.introPara2) - The text content of the span tag
 will be replaced at runtime with the name of the server to which the user
 was trying to connect. -->
 <!ENTITY certerror.introPara "The owner of <span class='hostname'/> has configured their website improperly.  To protect your information from being stolen, &brandShortName; has not connected to this website.">
-<!ENTITY certerror.introPara1 "&brandShortName; detected a potential security threat and did not continue to <span class='hostname'/>. If you visit this site, attackers could try to steal information like your passwords, emails, or credit cards.">
+<!ENTITY certerror.introPara2 "&brandShortName; detected a potential security threat and did not continue to <span class='hostname'/>. If you visit this site, attackers could try to steal information like your passwords, emails, or credit card details.">
 
 <!ENTITY certerror.expiredCert.secondPara "This issue is most likely because your computer clock is set to the wrong time, which would prevent &brandShortName; from connecting securely.">
 
 <!ENTITY certerror.whatCanYouDoAboutItTitle "What can you do about it?">
 
 <!ENTITY certerror.unknownIssuer.whatCanYouDoAboutIt "
 <p>The issue is most likely with the website, and there is nothing you can do to resolve it.</p>
 <p>If you are on a corporate network or using anti-virus software, you can reach out to the support teams for assistance. You can also notify the website’s administrator about the problem.</p>

--- a/devtools/server/actors/network-monitor.js
+++ b/devtools/server/actors/network-monitor.js
@@ -23,94 +23,90 @@ const NetworkMonitorActor = ActorClassWi
    *
    * @param object filters
    *        Contains an `outerWindowID` attribute when this is used across processes.
    *        Or a `window` attribute when instanciated in the same process.
    * @param number parentID (optional)
    *        To be removed, specify the ID of the Web console actor.
    *        This is used to fake emitting an event from it to prevent changing RDP
    *        behavior.
-   * @param nsIMessageManager messageManager (optional)
-   *        Passed only when it is instanciated across processes. This is the manager to
-   *        use to communicate with the other process.
-   * @param object stackTraceCollector (optional)
-   *        When the actor runs in the same process than the requests we are inspecting,
-   *        the web console actor hands over a shared instance to the stack trace
-   *        collector.
+   * @param nsIMessageManager messageManager
+   *        This is the manager to use to communicate with the console actor. When both
+   *        netmonitor and console actor runs in the same process, this is an instance
+   *        of MockMessageManager instead of a real message manager.
    */
-  initialize(conn, filters, parentID, messageManager, stackTraceCollector) {
+  initialize(conn, filters, parentID, messageManager) {
     Actor.prototype.initialize.call(this, conn);
 
     this.parentID = parentID;
     this.messageManager = messageManager;
-    this.stackTraceCollector = stackTraceCollector;
 
     // Immediately start watching for new request according to `filters`.
     // NetworkMonitor will call `onNetworkEvent` method.
     this.netMonitor = new NetworkMonitor(filters, this);
     this.netMonitor.init();
 
-    if (this.messageManager) {
-      this.stackTraces = new Set();
-      this.onStackTraceAvailable = this.onStackTraceAvailable.bind(this);
-      this.messageManager.addMessageListener("debug:request-stack-available",
-        this.onStackTraceAvailable);
-      this.onRequestContent = this.onRequestContent.bind(this);
-      this.messageManager.addMessageListener("debug:request-content",
-        this.onRequestContent);
-      this.onSetPreference = this.onSetPreference.bind(this);
-      this.messageManager.addMessageListener("debug:netmonitor-preference",
-        this.onSetPreference);
-      this.onGetNetworkEventActor = this.onGetNetworkEventActor.bind(this);
-      this.messageManager.addMessageListener("debug:get-network-event-actor",
-        this.onGetNetworkEventActor);
-      this.destroy = this.destroy.bind(this);
-      this.messageManager.addMessageListener("debug:destroy-network-monitor",
-        this.destroy);
+    this.stackTraces = new Set();
+    this.onStackTraceAvailable = this.onStackTraceAvailable.bind(this);
+    this.messageManager.addMessageListener("debug:request-stack-available",
+      this.onStackTraceAvailable);
+    this.onRequestContent = this.onRequestContent.bind(this);
+    this.messageManager.addMessageListener("debug:request-content",
+      this.onRequestContent);
+    this.onSetPreference = this.onSetPreference.bind(this);
+    this.messageManager.addMessageListener("debug:netmonitor-preference",
+      this.onSetPreference);
+    this.onGetNetworkEventActor = this.onGetNetworkEventActor.bind(this);
+    this.messageManager.addMessageListener("debug:get-network-event-actor",
+      this.onGetNetworkEventActor);
+    this.onDestroyMessage = this.onDestroyMessage.bind(this);
+    this.messageManager.addMessageListener("debug:destroy-network-monitor",
+      this.onDestroyMessage);
+  },
+
+  onDestroyMessage({ data }) {
+    if (data.actorID == this.parentID) {
+      this.destroy();
     }
   },
 
   destroy() {
     Actor.prototype.destroy.call(this);
 
     if (this.netMonitor) {
       this.netMonitor.destroy();
       this.netMonitor = null;
     }
 
+    this.stackTraces.clear();
     if (this.messageManager) {
-      this.stackTraces.clear();
       this.messageManager.removeMessageListener("debug:request-stack-available",
         this.onStackTraceAvailable);
       this.messageManager.removeMessageListener("debug:request-content",
         this.onRequestContent);
       this.messageManager.removeMessageListener("debug:netmonitor-preference",
         this.onSetPreference);
       this.messageManager.removeMessageListener("debug:get-network-event-actor",
         this.onGetNetworkEventActor);
       this.messageManager.removeMessageListener("debug:destroy-network-monitor",
-        this.destroy);
+        this.onDestroyMessage);
       this.messageManager = null;
     }
   },
 
   onStackTraceAvailable(msg) {
     const { channelId } = msg.data;
     if (!msg.data.stacktrace) {
       this.stackTraces.delete(channelId);
     } else {
       this.stackTraces.add(channelId);
     }
   },
 
-  getRequestContentForURL(url) {
-    const actor = this._networkEventActorsByURL.get(url);
-    if (!actor) {
-      return null;
-    }
+  getRequestContentForActor(actor) {
     const content = actor._response.content;
     if (actor._discardResponseBody || actor._truncated || !content || !content.size) {
       // Do not return the stylesheet text if there is no meaningful content or if it's
       // still loading. Let the caller handle it by doing its own separate request.
       return null;
     }
 
     if (content.text.type != "longString") {
@@ -128,17 +124,20 @@ const NetworkMonitorActor = ActorClassWi
     return {
       content: longStringActor.str,
       contentType: content.mimeType,
     };
   },
 
   onRequestContent(msg) {
     const { url } = msg.data;
-    const content = this.getRequestContentForURL(url);
+    const actor = this._networkEventActorsByURL.get(url);
+    // Always reply with a message, but with a null `content` if this instance
+    // did not processed this request
+    const content = actor ? this.getRequestContentForActor(actor) : null;
     this.messageManager.sendAsyncMessage("debug:request-content", {
       url,
       content,
     });
   },
 
   onSetPreference({ data }) {
     if ("saveRequestAndResponseBodies" in data) {
@@ -146,17 +145,20 @@ const NetworkMonitorActor = ActorClassWi
     }
     if ("throttleData" in data) {
       this.netMonitor.throttleData = data.throttleData;
     }
   },
 
   onGetNetworkEventActor({ data }) {
     const actor = this.getNetworkEventActor(data.channelId);
-    this.messageManager.sendAsyncMessage("debug:get-network-event-actor", actor.form());
+    this.messageManager.sendAsyncMessage("debug:get-network-event-actor", {
+      channelId: data.channelId,
+      actor: actor.form()
+    });
   },
 
   getNetworkEventActor(channelId) {
     let actor = this._netEvents.get(channelId);
     if (actor) {
       return actor;
     }
 
@@ -170,23 +172,19 @@ const NetworkMonitorActor = ActorClassWi
 
   // This method is called by NetworkMonitor instance when a new request is fired
   onNetworkEvent(event) {
     const { channelId } = event;
 
     const actor = this.getNetworkEventActor(channelId);
     this._netEvents.set(channelId, actor);
 
-    if (this.messageManager) {
-      event.cause.stacktrace = this.stackTraces.has(channelId);
-      if (event.cause.stacktrace) {
-        this.stackTraces.delete(channelId);
-      }
-    } else {
-      event.cause.stacktrace = this.stackTraceCollector.getStackTrace(channelId);
+    event.cause.stacktrace = this.stackTraces.has(channelId);
+    if (event.cause.stacktrace) {
+      this.stackTraces.delete(channelId);
     }
     actor.init(event);
 
     this._networkEventActorsByURL.set(actor._request.url, actor);
 
     const packet = {
       from: this.parentID,
       type: "networkEvent",

--- a/devtools/server/actors/webconsole.js
+++ b/devtools/server/actors/webconsole.js
@@ -25,16 +25,17 @@ loader.lazyRequireGetter(this, "StackTra
 loader.lazyRequireGetter(this, "JSPropertyProvider", "devtools/shared/webconsole/js-property-provider", true);
 loader.lazyRequireGetter(this, "Parser", "resource://devtools/shared/Parser.jsm", true);
 loader.lazyRequireGetter(this, "NetUtil", "resource://gre/modules/NetUtil.jsm", true);
 loader.lazyRequireGetter(this, "WebConsoleCommands", "devtools/server/actors/webconsole/utils", true);
 loader.lazyRequireGetter(this, "addWebConsoleCommands", "devtools/server/actors/webconsole/utils", true);
 loader.lazyRequireGetter(this, "formatCommand", "devtools/server/actors/webconsole/commands", true);
 loader.lazyRequireGetter(this, "isCommand", "devtools/server/actors/webconsole/commands", true);
 loader.lazyRequireGetter(this, "validCommands", "devtools/server/actors/webconsole/commands", true);
+loader.lazyRequireGetter(this, "createMessageManagerMocks", "devtools/server/actors/webconsole/message-manager-mock", true);
 loader.lazyRequireGetter(this, "CONSOLE_WORKER_IDS", "devtools/server/actors/webconsole/utils", true);
 loader.lazyRequireGetter(this, "WebConsoleUtils", "devtools/server/actors/webconsole/utils", true);
 loader.lazyRequireGetter(this, "EnvironmentActor", "devtools/server/actors/environment", true);
 loader.lazyRequireGetter(this, "EventEmitter", "devtools/shared/event-emitter");
 
 // Overwrite implemented listeners for workers so that we don't attempt
 // to load an unsupported module.
 if (isWorker) {
@@ -320,32 +321,23 @@ WebConsoleActor.prototype =
   /**
    * Destroy the current WebConsoleActor instance.
    */
   destroy() {
     if (this.consoleServiceListener) {
       this.consoleServiceListener.destroy();
       this.consoleServiceListener = null;
     }
-    if (this.networkMonitorActor) {
-      this.networkMonitorActor.destroy();
-      this.networkMonitorActor = null;
-    }
-    if (this.networkMonitorActorId) {
-      const messageManager = this.parentActor.messageManager;
-      if (messageManager) {
+    if (this.netmonitors) {
+      for (const { messageManager } of this.netmonitors) {
         messageManager.sendAsyncMessage("debug:destroy-network-monitor", {
-          actorId: this.networkMonitorActorId
+          actorID: this.actorID
         });
       }
-      this.networkMonitorActorId = null;
-    }
-    if (this.networkMonitorChildActor) {
-      this.networkMonitorChildActor.destroy();
-      this.networkMonitorChildActor = null;
+      this.netmonitors = null;
     }
     if (this.consoleAPIListener) {
       this.consoleAPIListener.destroy();
       this.consoleAPIListener = null;
     }
     if (this.stackTraceCollector) {
       this.stackTraceCollector.destroy();
       this.stackTraceCollector = null;
@@ -584,30 +576,16 @@ WebConsoleActor.prototype =
    * @param object request
    *        The JSON request object received from the Web Console client.
    * @return object
    *         The response object which holds the startedListeners array.
    */
   startListeners: async function(request) {
     const startedListeners = [];
     const window = !this.parentActor.isRootActor ? this.window : null;
-    let messageManager = null;
-
-    // Check if the actor is running in a child process (but only if
-    // Services.appinfo exists, to prevent startListeners to fail
-    // when the target is a Worker).
-    const processBoundary = Services.appinfo && (
-      Services.appinfo.processType != Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT
-    );
-
-    // Retrieve a message manager from the parent actor if this actor is
-    // not currently running in the main process.
-    if (processBoundary) {
-      messageManager = this.parentActor.messageManager;
-    }
 
     while (request.listeners.length > 0) {
       const listener = request.listeners.shift();
       switch (listener) {
         case "PageError":
           // Workers don't support this message type yet
           if (isWorker) {
             break;
@@ -629,48 +607,79 @@ WebConsoleActor.prototype =
           }
           startedListeners.push(listener);
           break;
         case "NetworkActivity":
           // Workers don't support this message type
           if (isWorker) {
             break;
           }
-          if (!this.networkMonitorActorId && !this.networkMonitorActor) {
-            // Create a StackTraceCollector that's going to be shared both by
-            // the NetworkMonitorActor running in the same process for service worker
-            // requests, as well with the NetworkMonitorActor running in the parent
-            // process. It will communicate via message manager for this one.
-            this.stackTraceCollector = new StackTraceCollector({ window },
-              messageManager);
-            this.stackTraceCollector.init();
+          if (!this.netmonitors) {
+            // Instanciate fake message managers used for service worker's netmonitor
+            // when running in the content process, and for netmonitor running in the
+            // same process when running in the parent process.
+            // `createMessageManagerMocks` returns a couple of connected messages
+            // managers that pass messages to each other to simulate the process
+            // boundary. We will use the first one for the webconsole-actor and the
+            // second one will be used by the netmonitor-actor.
+            const [ mmMockParent, mmMockChild ] = createMessageManagerMocks();
 
-            if (messageManager && processBoundary) {
+            // Maintain the list of message manager we should message to/listen from
+            // to support the netmonitor instances, also records actorID of each
+            // NetworkMonitorActor.
+            // Array of `{ messageManager, parentProcess }`.
+            // Where `parentProcess` is true for the netmonitor actor instanciated in the
+            // parent process.
+            this.netmonitors = [];
+
+            // Check if the actor is running in a content process
+            const isInContentProcess =
+              Services.appinfo.processType != Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT &&
+              this.parentActor.messageManager;
+            if (isInContentProcess) {
               // Start a network monitor in the parent process to listen to
-              // most requests than happen in parent
-              this.networkMonitorActorId = await this.conn.spawnActorInParentProcess(
+              // most requests that happen in parent. This one will communicate through
+              // `messageManager`.
+              await this.conn.spawnActorInParentProcess(
                 this.actorID, {
                   module: "devtools/server/actors/network-monitor",
                   constructor: "NetworkMonitorActor",
                   args: [
                     { outerWindowID: this.parentActor.outerWindowID },
                     this.actorID
                   ],
                 });
+              this.netmonitors.push({
+                messageManager: this.parentActor.messageManager,
+                parentProcess: true
+              });
+            }
 
-              // Spawn also one in the child to listen to service workers
-              this.networkMonitorChildActor = new NetworkMonitorActor(this.conn,
-                { window },
-                this.actorID,
-                null,
-                this.stackTraceCollector);
-            } else {
-              this.networkMonitorActor = new NetworkMonitorActor(this.conn, { window },
-                this.actorID, null, this.stackTraceCollector);
-            }
+            // When the console actor runs in the parent process, Netmonitor can be ran
+            // in the process and communicate through `messageManagerMock`.
+            // And while it runs in the content process, we also spawn one in the content
+            // to listen to requests that happen in the content process (for instance
+            // service workers requests)
+            new NetworkMonitorActor(this.conn,
+              { window },
+              this.actorID,
+              mmMockParent);
+
+            this.netmonitors.push({
+              messageManager: mmMockChild,
+              parentProcess: !isInContentProcess
+            });
+
+            // Create a StackTraceCollector that's going to be shared both by
+            // the NetworkMonitorActor running in the same process for service worker
+            // requests, as well with the NetworkMonitorActor running in the parent
+            // process. It will communicate via message manager for this one.
+            this.stackTraceCollector = new StackTraceCollector({ window },
+              this.netmonitors);
+            this.stackTraceCollector.init();
           }
           startedListeners.push(listener);
           break;
         case "FileActivity":
           // Workers don't support this message type
           if (isWorker) {
             break;
           }
@@ -759,32 +768,23 @@ WebConsoleActor.prototype =
         case "ConsoleAPI":
           if (this.consoleAPIListener) {
             this.consoleAPIListener.destroy();
             this.consoleAPIListener = null;
           }
           stoppedListeners.push(listener);
           break;
         case "NetworkActivity":
-          if (this.networkMonitorActor) {
-            this.networkMonitorActor.destroy();
-            this.networkMonitorActor = null;
-          }
-          if (this.networkMonitorActorId) {
-            const messageManager = this.parentActor.messageManager;
-            if (messageManager) {
+          if (this.netmonitors) {
+            for (const { messageManager } of this.netmonitors) {
               messageManager.sendAsyncMessage("debug:destroy-network-monitor", {
-                actorId: this.networkMonitorActorId
+                actorID: this.actorID
               });
             }
-            this.networkMonitorActorId = null;
-          }
-          if (this.networkMonitorChildActor) {
-            this.networkMonitorChildActor.destroy();
-            this.networkMonitorChildActor = null;
+            this.netmonitors = null;
           }
           if (this.stackTraceCollector) {
             this.stackTraceCollector.destroy();
             this.stackTraceCollector = null;
           }
           stoppedListeners.push(listener);
           break;
         case "FileActivity":
@@ -1247,41 +1247,29 @@ WebConsoleActor.prototype =
    *
    * @param object request
    *        The request message - which preferences need to be updated.
    */
   setPreferences: function(request) {
     for (const key in request.preferences) {
       this._prefs[key] = request.preferences[key];
 
-      if (key == "NetworkMonitor.saveRequestAndResponseBodies") {
-        if (this.networkMonitorActor) {
-          this.networkMonitorActor.netMonitor.saveRequestAndResponseBodies =
-            this._prefs[key];
-        }
-        if (this.networkMonitorChildActor) {
-          this.networkMonitorChildActor.netMonitor.saveRequestAndResponseBodies =
-            this._prefs[key];
-        }
-        if (this.networkMonitorActorId) {
-          const messageManager = this.parentActor.messageManager;
-          messageManager.sendAsyncMessage("debug:netmonitor-preference",
-            { saveRequestAndResponseBodies: this._prefs[key] });
-        }
-      } else if (key == "NetworkMonitor.throttleData") {
-        if (this.networkMonitorActor) {
-          this.networkMonitorActor.netMonitor.throttleData = this._prefs[key];
-        }
-        if (this.networkMonitorChildActor) {
-          this.networkMonitorChildActor.netMonitor.throttleData = this._prefs[key];
-        }
-        if (this.networkMonitorActorId) {
-          const messageManager = this.parentActor.messageManager;
-          messageManager.sendAsyncMessage("debug:netmonitor-preference",
-            { throttleData: this._prefs[key] });
+      if (this.netmonitors) {
+        if (key == "NetworkMonitor.saveRequestAndResponseBodies") {
+          for (const { messageManager } of this.netmonitors) {
+            messageManager.sendAsyncMessage("debug:netmonitor-preference", {
+              saveRequestAndResponseBodies: this._prefs[key]
+            });
+          }
+        } else if (key == "NetworkMonitor.throttleData") {
+          for (const { messageManager } of this.netmonitors) {
+            messageManager.sendAsyncMessage("debug:netmonitor-preference", {
+              throttleData: this._prefs[key]
+            });
+          }
         }
       }
     }
     return { updated: Object.keys(request.preferences) };
   },
 
   // End of request handlers.
 
@@ -1813,36 +1801,40 @@ WebConsoleActor.prototype =
    * Get the NetworkEventActor for a given URL that may have been noticed by the network
    * listener.  Requests are added when they start, so the actor might not yet have all
    * data for the request until it has completed.
    *
    * @param string url
    *        The URL of the request to search for.
    */
   getRequestContentForURL(url) {
-    // When running in Parent Process, call the NetworkMonitorActor directly.
-    if (this.networkMonitorActor) {
-      return this.networkMonitorActor.getRequestContentForURL(url);
-    } else if (this.networkMonitorActorId) {
-      // Otherwise, if the netmonitor is started, but on the parent process,
-      // pipe the data through the message manager
-      const messageManager = this.parentActor.messageManager;
-      return new Promise(resolve => {
-        const onMessage = ({ data }) => {
-          if (data.url == url) {
+    if (!this.netmonitors) {
+      return null;
+    }
+    return new Promise(resolve => {
+      let messagesReceived = 0;
+      const onMessage = ({ data }) => {
+        if (data.url != url) {
+          return;
+        }
+        messagesReceived++;
+        // Either use the first response with a content, or return a null content
+        // if we received the responses from all the message managers.
+        if (data.content || messagesReceived == this.netmonitors.length) {
+          for (const { messageManager } of this.netmonitors) {
             messageManager.removeMessageListener("debug:request-content", onMessage);
-            resolve(data.content);
           }
-        };
+          resolve(data.content);
+        }
+      };
+      for (const { messageManager } of this.netmonitors) {
         messageManager.addMessageListener("debug:request-content", onMessage);
         messageManager.sendAsyncMessage("debug:request-content", { url });
-      });
-    }
-    // Finally, if the netmonitor is not started at all, return null
-    return null;
+      }
+    });
   },
 
   /**
    * Send a new HTTP request from the target's window.
    *
    * @param object message
    *        Object with 'request' - the HTTP request details.
    */
@@ -1878,40 +1870,38 @@ WebConsoleActor.prototype =
       const bodyStream = Cc["@mozilla.org/io/string-input-stream;1"]
         .createInstance(Ci.nsIStringInputStream);
       bodyStream.setData(body, body.length);
       channel.explicitSetUploadStream(bodyStream, null, -1, method, false);
     }
 
     NetUtil.asyncFetch(channel, () => {});
 
-    // When running in Parent Process, call the NetworkMonitorActor directly.
+    if (!this.netmonitors) {
+      return null;
+    }
     const { channelId } = channel;
-    if (this.networkMonitorActor) {
-      const actor = this.networkMonitorActor.getNetworkEventActor(channelId);
-      return {
-        eventActor: actor.form()
-      };
-    } else if (this.networkMonitorActorId) {
-      // Otherwise, if the netmonitor is started, but on the parent process,
-      // pipe the data through the message manager
-      const messageManager = this.parentActor.messageManager;
-      return new Promise(resolve => {
-        const onMessage = ({ data }) => {
+    // Only query the NetworkMonitorActor running in the parent process, where the
+    // request will be done. There always is one listener running in the parent process,
+    // see startListeners.
+    const netmonitor = this.netmonitors.filter(({ parentProcess }) => parentProcess)[0];
+    const { messageManager } = netmonitor;
+    return new Promise(resolve => {
+      const onMessage = ({ data }) => {
+        if (data.channelId == channelId) {
           messageManager.removeMessageListener("debug:get-network-event-actor",
             onMessage);
           resolve({
-            eventActor: data
+            eventActor: data.actor
           });
-        };
-        messageManager.addMessageListener("debug:get-network-event-actor", onMessage);
-        messageManager.sendAsyncMessage("debug:get-network-event-actor", { channelId });
-      });
-    }
-    return null;
+        }
+      };
+      messageManager.addMessageListener("debug:get-network-event-actor", onMessage);
+      messageManager.sendAsyncMessage("debug:get-network-event-actor", { channelId });
+    });
   },
 
   /**
    * Handler for file activity. This method sends the file request information
    * to the remote Web Console client.
    *
    * @see ConsoleProgressListener
    * @param string fileURI

new file mode 100644
--- /dev/null
+++ b/devtools/server/actors/webconsole/message-manager-mock.js
@@ -0,0 +1,68 @@
+/* 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";
+
+/**
+ * Implements a fake MessageManager class that allows to use the message
+ * manager API within the same process. This implementation will forward
+ * messages within the same process.
+ *
+ * It helps having the same codepath for actors being evaluated in the same
+ * process *and* in a remote one.
+ */
+function MessageManagerMock() {
+  this._listeners = new Map();
+}
+MessageManagerMock.prototype = {
+  addMessageListener(name, listener) {
+    let listeners = this._listeners.get(name);
+    if (!listeners) {
+      listeners = [];
+      this._listeners.set(name, listeners);
+    }
+    if (!listeners.includes(listener)) {
+      listeners.push(listener);
+    }
+  },
+  removeMessageListener(name, listener) {
+    const listeners = this._listeners.get(name);
+    const idx = listeners.indexOf(listener);
+    listeners.splice(idx, 1);
+  },
+  sendAsyncMessage(name, data) {
+    this.other.internalSendAsyncMessage(name, data);
+  },
+  internalSendAsyncMessage(name, data) {
+    const listeners = this._listeners.get(name);
+    if (!listeners) {
+      return;
+    }
+    const message = {
+      target: this,
+      data
+    };
+    for (const listener of listeners) {
+      if (typeof listener === "object" &&
+          typeof listener.receiveMessage === "function") {
+        listener.receiveMessage(message);
+      } else if (typeof listener === "function") {
+        listener(message);
+      }
+    }
+  },
+};
+
+/**
+ * Create two MessageManager mocks, connected to each others.
+ * Calling sendAsyncMessage on the first will dispatch messages on the second one,
+ * and the other way around
+ */
+exports.createMessageManagerMocks = function() {
+  const a = new MessageManagerMock();
+  const b = new MessageManagerMock();
+  a.other = b;
+  b.other = a;
+  return [a, b];
+};

--- a/devtools/server/actors/webconsole/moz.build
+++ b/devtools/server/actors/webconsole/moz.build
@@ -3,12 +3,13 @@
 # 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/.
 
 DevToolsModules(
     'commands.js',
     'content-process-forward.js',
     'listeners.js',
+    'message-manager-mock.js',
     'screenshot.js',
     'utils.js',
     'worker-listeners.js',
 )

--- a/devtools/shared/webconsole/network-helper.js
+++ b/devtools/shared/webconsole/network-helper.js
@@ -194,32 +194,16 @@ var NetworkHelper = {
 
         return this.readAndConvertFromStream(descriptor, charset);
       }
     }
     return null;
   },
 
   /**
-   * Gets the web appId that is associated with request.
-   *
-   * @param nsIHttpChannel request
-   * @returns number|null
-   *          The appId for the given request, if available.
-   */
-  getAppIdForRequest: function(request) {
-    try {
-      return this.getRequestLoadContext(request).appId;
-    } catch (ex) {
-      // request loadContent is not always available.
-    }
-    return null;
-  },
-
-  /**
    * Gets the topFrameElement that is associated with request. This
    * works in single-process and multiprocess contexts. It may cross
    * the content/chrome boundary.
    *
    * @param nsIHttpChannel request
    * @returns Element|null
    *          The top frame element for the given request.
    */

--- a/devtools/shared/webconsole/network-monitor.js
+++ b/devtools/shared/webconsole/network-monitor.js
@@ -12,22 +12,25 @@ const Services = require("Services");
 const { XPCOMUtils } = require("resource://gre/modules/XPCOMUtils.jsm");
 
 loader.lazyRequireGetter(this, "NetworkHelper",
                          "devtools/shared/webconsole/network-helper");
 loader.lazyRequireGetter(this, "DevToolsUtils",
                          "devtools/shared/DevToolsUtils");
 loader.lazyRequireGetter(this, "flags",
                          "devtools/shared/flags");
+loader.lazyRequireGetter(this, "NetworkThrottleManager",
+                         "devtools/shared/webconsole/throttle", true);
+loader.lazyRequireGetter(this, "CacheEntry",
+                         "devtools/shared/platform/cache-entry", true);
 loader.lazyImporter(this, "NetUtil", "resource://gre/modules/NetUtil.jsm");
 loader.lazyServiceGetter(this, "gActivityDistributor",
                          "@mozilla.org/network/http-activity-distributor;1",
                          "nsIHttpActivityDistributor");
-const {NetworkThrottleManager} = require("devtools/shared/webconsole/throttle");
-const {CacheEntry} = require("devtools/shared/platform/cache-entry");
+
 // Network logging
 
 // The maximum uint32 value.
 const PR_UINT32_MAX = 4294967295;
 
 // HTTP status codes.
 const HTTP_MOVED_PERMANENTLY = 301;
 const HTTP_FOUND = 302;
@@ -42,17 +45,17 @@ const HTTP_TEMPORARY_REDIRECT = 307;
  *        Request to check.
  * @param filters
  *        NetworkMonitor filters to match against.
  * @return boolean
  *         True if the network request should be logged, false otherwise.
  */
 function matchRequest(channel, filters) {
   // Log everything if no filter is specified
-  if (!filters.outerWindowID && !filters.window && !filters.appId) {
+  if (!filters.outerWindowID && !filters.window) {
     return true;
   }
 
   // Ignore requests from chrome or add-on code when we are monitoring
   // content.
   // TODO: one particular test (browser_styleeditor_fetch-from-cache.js) needs
   // the flags.testing check. We will move to a better way to serve
   // its needs in bug 1167188, where this check should be removed.
@@ -88,23 +91,16 @@ function matchRequest(channel, filters) 
         }
       } catch (e) {
         // outerWindowID getter from browser.xml (non-remote <xul:browser>) may
         // throw when closing a tab while resources are still loading.
       }
     }
   }
 
-  if (filters.appId) {
-    const appId = NetworkHelper.getAppIdForRequest(channel);
-    if (appId && appId == filters.appId) {
-      return true;
-    }
-  }
-
   return false;
 }
 
 /**
  * This is a nsIChannelEventSink implementation that monitors channel redirects and
  * informs the registered StackTraceCollector about the old and new channels.
  */
 const SINK_CLASS_DESCRIPTION = "NetworkMonitor Channel Event Sink";
@@ -172,43 +168,43 @@ ChannelEventSinkFactory.unregister = fun
 
 ChannelEventSinkFactory.getService = function() {
   // Make sure the ChannelEventSink service is registered before accessing it
   ChannelEventSinkFactory.register();
 
   return Cc[SINK_CONTRACT_ID].getService(Ci.nsIChannelEventSink).wrappedJSObject;
 };
 
-function StackTraceCollector(filters, messageManager) {
+function StackTraceCollector(filters, netmonitors) {
   this.filters = filters;
   this.stacktracesById = new Map();
-  this.messageManager = messageManager;
+  this.netmonitors = netmonitors;
 }
 
 StackTraceCollector.prototype = {
   init() {
     Services.obs.addObserver(this, "http-on-opening-request");
     ChannelEventSinkFactory.getService().registerCollector(this);
-    if (this.messageManager) {
-      this.onGetStack = this.onGetStack.bind(this);
-      this.messageManager.addMessageListener("debug:request-stack", this.onGetStack);
+    this.onGetStack = this.onGetStack.bind(this);
+    for (const { messageManager } of this.netmonitors) {
+      messageManager.addMessageListener("debug:request-stack", this.onGetStack);
     }
   },
 
   destroy() {
     Services.obs.removeObserver(this, "http-on-opening-request");
     ChannelEventSinkFactory.getService().unregisterCollector(this);
-    if (this.messageManager) {
-      this.messageManager.removeMessageListener("debug:request-stack", this.onGetStack);
+    for (const { messageManager } of this.netmonitors) {
+      messageManager.removeMessageListener("debug:request-stack", this.onGetStack);
     }
   },
 
   _saveStackTrace(channel, stacktrace) {
-    if (this.messageManager) {
-      this.messageManager.sendAsyncMessage("debug:request-stack-available", {
+    for (const { messageManager } of this.netmonitors) {
+      messageManager.sendAsyncMessage("debug:request-stack-available", {
         channelId: channel.channelId,
         stacktrace: stacktrace && stacktrace.length > 0
       });
     }
     this.stacktracesById.set(channel.channelId, stacktrace);
   },
 
   observe(subject) {
@@ -258,19 +254,20 @@ StackTraceCollector.prototype = {
 
   getStackTrace(channelId) {
     const trace = this.stacktracesById.get(channelId);
     this.stacktracesById.delete(channelId);
     return trace;
   },
 
   onGetStack(msg) {
+    const messageManager = msg.target;
     const channelId = msg.data;
     const stack = this.getStackTrace(channelId);
-    this.messageManager.sendAsyncMessage("debug:request-stack", {
+    messageManager.sendAsyncMessage("debug:request-stack", {
       channelId,
       stack,
     });
   },
 };
 
 exports.StackTraceCollector = StackTraceCollector;
 
@@ -764,17 +761,16 @@ NetworkResponseListener.prototype = {
  * http-on-examine-response notifications. All network request information is
  * routed to the remote Web Console.
  *
  * @constructor
  * @param object filters
  *        Object with the filters to use for network requests:
  *        - window (nsIDOMWindow): filter network requests by the associated
  *          window object.
- *        - appId (number): filter requests by the appId.
  *        - outerWindowID (number): filter requests by their top frame's outerWindowID.
  *        Filters are optional. If any of these filters match the request is
  *        logged (OR is applied). If no filter is provided then all requests are
  *        logged.
  * @param object owner
  *        The network monitor owner. This object needs to hold:
  *        - onNetworkEvent(requestInfo)
  *          This method is invoked once for every new network request and it is

--- a/dom/base/AttrArray.h
+++ b/dom/base/AttrArray.h
@@ -176,16 +176,21 @@ private:
   nsresult DoUpdateMappedAttrRuleMapper(nsMappedAttributeElement& aElement);
 
   struct InternalAttr
   {
     nsAttrName mName;
     nsAttrValue mValue;
   };
 
+#ifdef _MSC_VER
+// Disable MSVC warning 'nonstandard extension used: zero-sized array in struct/union'
+#pragma warning(push)
+#pragma warning(disable:4200)
+#endif
   class Impl
   {
   public:
 
     constexpr static size_t AllocationSizeForAttributes(uint32_t aAttrCount)
     {
       return sizeof(Impl) + aAttrCount * sizeof(InternalAttr);
     }
@@ -208,16 +213,20 @@ private:
     uint32_t mCapacity; // In number of InternalAttrs
 
     // Manually refcounted.
     nsMappedAttributes* mMappedAttrs;
 
     // Allocated in the same buffer as `Impl`.
     InternalAttr mBuffer[0];
   };
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
 
   mozilla::Span<InternalAttr> NonMappedAttrs()
   {
     return mImpl ? mImpl->NonMappedAttrs() : mozilla::Span<InternalAttr>();
   }
 
   mozilla::Span<const InternalAttr> NonMappedAttrs() const
   {

--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -22637,27 +22637,35 @@ DeleteDatabaseOp::LoadPreviousVersion(ns
   rv = OpenDatabaseAndHandleBusy(ss, aDatabaseFile, getter_AddRefs(connection));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return;
   }
 
 #ifdef DEBUG
   {
     nsCOMPtr<mozIStorageStatement> stmt;
-    MOZ_ALWAYS_SUCCEEDS(
-      connection->CreateStatement(NS_LITERAL_CSTRING(
-        "SELECT name "
-          "FROM database"
-        ), getter_AddRefs(stmt)));
+    rv = connection->CreateStatement(NS_LITERAL_CSTRING(
+      "SELECT name "
+      "FROM database"
+    ), getter_AddRefs(stmt));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return;
+    }
 
     bool hasResult;
-    MOZ_ALWAYS_SUCCEEDS(stmt->ExecuteStep(&hasResult));
+    rv = stmt->ExecuteStep(&hasResult);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return;
+    }
 
     nsString databaseName;
-    MOZ_ALWAYS_SUCCEEDS(stmt->GetString(0, databaseName));
+    rv = stmt->GetString(0, databaseName);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return;
+    }
 
     MOZ_ASSERT(mCommonParams.metadata().name() == databaseName);
   }
 #endif
 
   nsCOMPtr<mozIStorageStatement> stmt;
   rv = connection->CreateStatement(NS_LITERAL_CSTRING(
     "SELECT version "

--- a/dom/media/webaudio/test/mochitest.ini
+++ b/dom/media/webaudio/test/mochitest.ini
@@ -216,16 +216,21 @@ skip-if = toolkit == 'android' # bug 109
 [test_pannerNodeTail.html]
 [test_pannerNode_maxDistance.html]
 [test_setValueCurveWithNonFiniteElements.html]
 [test_stereoPannerNode.html]
 [test_stereoPannerNodePassThrough.html]
 [test_periodicWave.html]
 [test_periodicWaveDisableNormalization.html]
 [test_periodicWaveBandLimiting.html]
+[test_retrospective-exponentialRampToValueAtTime.html]
+[test_retrospective-linearRampToValueAtTime.html]
+[test_retrospective-setTargetAtTime.html]
+[test_retrospective-setValueAtTime.html]
+[test_retrospective-setValueCurveAtTime.html]
 [test_ScriptProcessorCollected1.html]
 [test_scriptProcessorNode.html]
 [test_scriptProcessorNodeChannelCount.html]
 [test_scriptProcessorNodePassThrough.html]
 [test_scriptProcessorNode_playbackTime1.html]
 [test_scriptProcessorNodeZeroInputOutput.html]
 [test_scriptProcessorNodeNotConnected.html]
 [test_sequentialBufferSourceWithResampling.html]

new file mode 100644
--- /dev/null
+++ b/dom/media/webaudio/test/test_retrospective-exponentialRampToValueAtTime.html
@@ -0,0 +1,51 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Test exponentialRampToValue with end time in the past</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+function do_test(t, context) {
+  var source = context.createConstantSource();
+  source.start();
+
+  var test = context.createGain();
+  test.gain.exponentialRampToValueAtTime(0.1, 0.5*context.currentTime);
+  test.gain.exponentialRampToValueAtTime(0.9, 2.0);
+
+  var reference = context.createGain();
+  reference.gain.exponentialRampToValueAtTime(0.1, context.currentTime);
+  reference.gain.exponentialRampToValueAtTime(0.9, 2.0);
+
+  source.connect(test);
+  source.connect(reference);
+
+  var merger = context.createChannelMerger();
+  test.connect(merger, 0, 0);
+  reference.connect(merger, 0, 1);
+
+  var processor = context.createScriptProcessor(0, 2, 0);
+  merger.connect(processor);
+  processor.onaudioprocess =
+    t.step_func_done((e) => {
+      source.stop();
+      processor.onaudioprocess = null;
+
+      var testValue = e.inputBuffer.getChannelData(0)[0];
+      var referenceValue = e.inputBuffer.getChannelData(1)[0];
+
+      assert_equals(testValue, referenceValue,
+                        "value matches expected");
+    });
+}
+
+async_test(function(t) {
+  var context = new AudioContext;
+  (function waitForTimeAdvance() {
+    if (context.currentTime == 0) {
+      t.step_timeout(waitForTimeAdvance, 0);
+    } else {
+      do_test(t, context);
+    }
+  })();
+});
+</script>

new file mode 100644
--- /dev/null
+++ b/dom/media/webaudio/test/test_retrospective-linearRampToValueAtTime.html
@@ -0,0 +1,51 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Test linearRampToValue with end time in the past</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+function do_test(t, context) {
+  var source = context.createConstantSource();
+  source.start();
+
+  var test = context.createGain();
+  test.gain.linearRampToValueAtTime(0.1, 0.5*context.currentTime);
+  test.gain.linearRampToValueAtTime(0.9, 2.0);
+
+  var reference = context.createGain();
+  reference.gain.linearRampToValueAtTime(0.1, context.currentTime);
+  reference.gain.linearRampToValueAtTime(0.9, 2.0);
+
+  source.connect(test);
+  source.connect(reference);
+
+  var merger = context.createChannelMerger();
+  test.connect(merger, 0, 0);
+  reference.connect(merger, 0, 1);
+
+  var processor = context.createScriptProcessor(0, 2, 0);
+  merger.connect(processor);
+  processor.onaudioprocess =
+    t.step_func_done((e) => {
+      source.stop();
+      processor.onaudioprocess = null;
+
+      var testValue = e.inputBuffer.getChannelData(0)[0];
+      var referenceValue = e.inputBuffer.getChannelData(1)[0];
+
+      assert_equals(testValue, referenceValue,
+                        "value matches expected");
+    });
+}
+
+async_test(function(t) {
+  var context = new AudioContext;
+  (function waitForTimeAdvance() {
+    if (context.currentTime == 0) {
+      t.step_timeout(waitForTimeAdvance, 0);
+    } else {
+      do_test(t, context);
+    }
+  })();
+});
+</script>

new file mode 100644
--- /dev/null
+++ b/dom/media/webaudio/test/test_retrospective-setTargetAtTime.html
@@ -0,0 +1,51 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Test setTargetAtTime with start time in the past</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+function do_test(t, context) {
+  var source = context.createConstantSource();
+  source.start();
+
+  var test = context.createGain();
+  test.gain.setTargetAtTime(0.1, 0.5*context.currentTime, 0.1);
+  test.gain.linearRampToValueAtTime(0.9, 2.0);
+
+  var reference = context.createGain();
+  reference.gain.setTargetAtTime(0.1, context.currentTime, 0.1);
+  reference.gain.linearRampToValueAtTime(0.9, 2.0);
+
+  source.connect(test);
+  source.connect(reference);
+
+  var merger = context.createChannelMerger();
+  test.connect(merger, 0, 0);
+  reference.connect(merger, 0, 1);
+
+  var processor = context.createScriptProcessor(0, 2, 0);
+  merger.connect(processor);
+  processor.onaudioprocess =
+    t.step_func_done((e) => {
+      source.stop();
+      processor.onaudioprocess = null;
+
+      var testValue = e.inputBuffer.getChannelData(0)[0];
+      var referenceValue = e.inputBuffer.getChannelData(1)[0];
+
+      assert_equals(testValue, referenceValue,
+                        "value matches expected");
+    });
+}
+
+async_test(function(t) {
+  var context = new AudioContext;
+  (function waitForTimeAdvance() {
+    if (context.currentTime == 0) {
+      t.step_timeout(waitForTimeAdvance, 0);
+    } else {
+      do_test(t, context);
+    }
+  })();
+});
+</script>

new file mode 100644
--- /dev/null
+++ b/dom/media/webaudio/test/test_retrospective-setValueAtTime.html
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<title>Test setValueAtTime with startTime in the past</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+function do_test(t, context) {
+  var source = context.createConstantSource();
+  source.start();
+
+  // Use a ramp of slope 1/sample to measure time.
+  // The end value is the extent of exact precision in single precision float.
+  const rampEnd = Math.pow(2, 24);
+  const rampEndSeconds = rampEnd / context.sampleRate;
+  var test = context.createGain();
+  test.gain.setValueAtTime(0.0, 0.5*context.currentTime);
+  test.gain.linearRampToValueAtTime(rampEnd, rampEndSeconds);
+
+  var reference = context.createGain();
+  reference.gain.setValueAtTime(0.0, context.currentTime);
+  reference.gain.linearRampToValueAtTime(rampEnd, rampEndSeconds);
+
+  source.connect(test);
+  source.connect(reference);
+
+  var merger = context.createChannelMerger();
+  test.connect(merger, 0, 0);
+  reference.connect(merger, 0, 1);
+
+  var processor = context.createScriptProcessor(0, 2, 0);
+  merger.connect(processor);
+  processor.onaudioprocess =
+    t.step_func_done((e) => {
+      source.stop();
+      processor.onaudioprocess = null;
+
+      var testValue = e.inputBuffer.getChannelData(0)[0];
+      var referenceValue = e.inputBuffer.getChannelData(1)[0];
+
+      assert_equals(testValue, referenceValue,
+                        "ramp value matches expected");
+    });
+}
+
+async_test(function(t) {
+  var context = new AudioContext;
+  (function waitForTimeAdvance() {
+    if (context.currentTime == 0) {
+      t.step_timeout(waitForTimeAdvance, 0);
+    } else {
+      do_test(t, context);
+    }
+  })();
+});
+</script>

new file mode 100644
--- /dev/null
+++ b/dom/media/webaudio/test/test_retrospective-setValueCurveAtTime.html
@@ -0,0 +1,49 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Test SetValueCurve with start time in the past</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+function do_test(t, context) {
+  var source = context.createConstantSource();
+  source.start();
+
+  var test = context.createGain();
+  test.gain.setValueCurveAtTime(new Float32Array([1.0, 0.1]), 0.0, 1.0);
+
+  var reference = context.createGain();
+  reference.gain.setValueCurveAtTime(new Float32Array([1.0, 0.1]), 0.5*context.currentTime, 1.0);
+
+  source.connect(test);
+  source.connect(reference);
+
+  var merger = context.createChannelMerger();
+  test.connect(merger, 0, 0);
+  reference.connect(merger, 0, 1);
+
+  var processor = context.createScriptProcessor(0, 2, 0);
+  merger.connect(processor);
+  processor.onaudioprocess =
+    t.step_func_done((e) => {
+      source.stop();
+      processor.onaudioprocess = null;
+
+      var testValue = e.inputBuffer.getChannelData(0)[0];
+      var referenceValue = e.inputBuffer.getChannelData(1)[0];
+
+      assert_equals(testValue, referenceValue,
+                        "value matches expected");
+    });
+}
+
+async_test(function(t) {
+  var context = new AudioContext;
+  (function waitForTimeAdvance() {
+    if (context.currentTime == 0) {
+      t.step_timeout(waitForTimeAdvance, 0);
+    } else {
+      do_test(t, context);
+    }
+  })();
+});
+</script>

--- a/editor/libeditor/EditorBase.cpp
+++ b/editor/libeditor/EditorBase.cpp
@@ -4532,17 +4532,17 @@ EditorBase::ClearSelection()
   RefPtr<Selection> selection = GetSelection();
   NS_ENSURE_TRUE(selection, NS_ERROR_FAILURE);
   ErrorResult rv;
   selection->RemoveAllRanges(rv);
   return rv.StealNSResult();
 }
 
 already_AddRefed<Element>
-EditorBase::CreateHTMLContent(nsAtom* aTag)
+EditorBase::CreateHTMLContent(const nsAtom* aTag)
 {
   MOZ_ASSERT(aTag);
 
   nsCOMPtr<nsIDocument> doc = GetDocument();
   if (!doc) {
     return nullptr;
   }
 

--- a/editor/libeditor/EditorBase.h
+++ b/editor/libeditor/EditorBase.h
@@ -1041,17 +1041,17 @@ protected: // May be called by friends.
                                             const nsAString& aValue,
                                             bool aSuppressTransaction) = 0;
 
   /**
    * Method to replace certain CreateElementNS() calls.
    *
    * @param aTag        Tag you want.
    */
-  already_AddRefed<Element> CreateHTMLContent(nsAtom* aTag);
+  already_AddRefed<Element> CreateHTMLContent(const nsAtom* aTag);
 
   /**
    * Creates text node which is marked as "maybe modified frequently".
    */
   static already_AddRefed<nsTextNode> CreateTextNode(nsIDocument& aDocument,
                                                      const nsAString& aData);
 
   /**

--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -1462,17 +1462,17 @@ HTMLEditor::RebuildDocumentFromSource(co
       // assume there is no head, the entire source is body
       nsresult rv = LoadHTML(body + aSourceString);
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return rv;
       }
     }
 
     RefPtr<Element> divElement =
-      CreateElementWithDefaults(NS_LITERAL_STRING("div"));
+      CreateElementWithDefaults(*nsGkAtoms::div);
     if (NS_WARN_IF(!divElement)) {
       return NS_ERROR_FAILURE;
     }
     CloneAttributesWithTransaction(*rootElement, *divElement);
 
     return MaybeCollapseSelectionAtFirstEditableNode(false);
   }
 
@@ -2800,84 +2800,86 @@ HTMLEditor::GetSelectedElement(Selection
       }
     }
     iter->Next();
   }
   return selectedElement.forget();
 }
 
 already_AddRefed<Element>
-HTMLEditor::CreateElementWithDefaults(const nsAString& aTagName)
+HTMLEditor::CreateElementWithDefaults(const nsAtom& aTagName)
 {
-  MOZ_ASSERT(!aTagName.IsEmpty());
-
-  nsAutoString tagName(aTagName);
-  ToLowerCase(tagName);
-  nsAutoString realTagName;
-
-  if (IsLinkTag(tagName) || IsNamedAnchorTag(tagName)) {
-    realTagName.Assign('a');
-  } else {
-    realTagName = tagName;
-  }
+  // NOTE: Despite of public method, this can be called for internal use.
+
+  const nsAtom* realTagName =
+    IsLinkTag(aTagName) || IsNamedAnchorTag(aTagName) ? nsGkAtoms::a :
+                                                        &aTagName;
+
   // We don't use editor's CreateElement because we don't want to go through
   // the transaction system
 
   // New call to use instead to get proper HTML element, bug 39919
-  RefPtr<nsAtom> realTagAtom = NS_Atomize(realTagName);
-  RefPtr<Element> newElement = CreateHTMLContent(realTagAtom);
+  RefPtr<Element> newElement = CreateHTMLContent(realTagName);
   if (!newElement) {
     return nullptr;
   }
 
   // Mark the new element dirty, so it will be formatted
-  ErrorResult rv;
+  // XXX Don't we need to check the error result of setting _moz_dirty attr?
+  IgnoredErrorResult rv;
   newElement->SetAttribute(NS_LITERAL_STRING("_moz_dirty"), EmptyString(), rv);
 
   // Set default values for new elements
-  if (tagName.EqualsLiteral("table")) {
+  if (realTagName == nsGkAtoms::table) {
     newElement->SetAttribute(NS_LITERAL_STRING("cellpadding"),
                              NS_LITERAL_STRING("2"), rv);
     if (NS_WARN_IF(rv.Failed())) {
-      rv.SuppressException();
       return nullptr;
     }
     newElement->SetAttribute(NS_LITERAL_STRING("cellspacing"),
                              NS_LITERAL_STRING("2"), rv);
     if (NS_WARN_IF(rv.Failed())) {
-      rv.SuppressException();
       return nullptr;
     }
     newElement->SetAttribute(NS_LITERAL_STRING("border"),
                              NS_LITERAL_STRING("1"), rv);
     if (NS_WARN_IF(rv.Failed())) {
-      rv.SuppressException();
       return nullptr;
     }
-  } else if (tagName.EqualsLiteral("td")) {
+  } else if (realTagName == nsGkAtoms::td) {
     nsresult rv =
       SetAttributeOrEquivalent(
         newElement, nsGkAtoms::valign, NS_LITERAL_STRING("top"), true);
-    NS_ENSURE_SUCCESS(rv, nullptr);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return nullptr;
+    }
   }
   // ADD OTHER TAGS HERE
 
   return newElement.forget();
 }
 
 NS_IMETHODIMP
 HTMLEditor::CreateElementWithDefaults(const nsAString& aTagName,
                                       Element** aReturn)
 {
-  NS_ENSURE_TRUE(!aTagName.IsEmpty() && aReturn, NS_ERROR_NULL_POINTER);
+  if (NS_WARN_IF(aTagName.IsEmpty()) || NS_WARN_IF(!aReturn)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
   *aReturn = nullptr;
 
-  nsCOMPtr<Element> newElement = CreateElementWithDefaults(aTagName);
-  NS_ENSURE_TRUE(newElement, NS_ERROR_FAILURE);
-
+  RefPtr<nsAtom> tagName = GetLowerCaseNameAtom(aTagName);
+  if (NS_WARN_IF(!tagName)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  RefPtr<Element> newElement = CreateElementWithDefaults(*tagName);
+  if (NS_WARN_IF(!newElement)) {
+    return NS_ERROR_FAILURE;
+  }
   newElement.forget(aReturn);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 HTMLEditor::InsertLinkAroundSelection(Element* aAnchorElement)
 {
   NS_ENSURE_TRUE(aAnchorElement, NS_ERROR_NULL_POINTER);

--- a/editor/libeditor/HTMLEditor.h
+++ b/editor/libeditor/HTMLEditor.h
@@ -176,16 +176,32 @@ public:
 
   /**
    * OnInputLineBreak() is called when user inputs a line break with
    * Shift + Enter or something.
    */
   nsresult OnInputLineBreak();
 
   /**
+   * CreateElementWithDefaults() creates new element whose name is
+   * aTagName with some default attributes are set.  Note that this is a
+   * public utility method.  I.e., just creates element, not insert it
+   * into the DOM tree.
+   * NOTE: This is available for internal use too since this does not change
+   *       the DOM tree nor undo transactions, and does not refer Selection,
+   *       HTMLEditRules, etc.
+   *
+   * @param aTagName            The new element's tag name.  If the name is
+   *                            one of "href", "anchor" or "namedanchor",
+   *                            this creates an <a> element.
+   * @return                    Newly created element.
+   */
+  already_AddRefed<Element> CreateElementWithDefaults(const nsAtom& aTagName);
+
+  /**
    * Indent or outdent content around Selection.
    */
   nsresult IndentAsAction();
   nsresult OutdentAsAction();
 
   /**
    * event callback when a mouse button is pressed
    * @param aX      [IN] horizontal position of the pointer
@@ -1472,20 +1488,17 @@ protected: // Shouldn't be used by frien
                               nsAtom* aAttribute,
                               const nsAString* aValue);
   nsresult SetInlinePropertyOnNodeImpl(nsIContent& aNode,
                                        nsAtom& aProperty,
                                        nsAtom* aAttribute,
                                        const nsAString& aValue);
   typedef enum { eInserted, eAppended } InsertedOrAppended;
   void DoContentInserted(nsIContent* aChild, InsertedOrAppended);
-  // XXX Shouldn't this used by external classes instead of nsIHTMLEditor's
-  //     method?
-  already_AddRefed<Element> CreateElementWithDefaults(
-                              const nsAString& aTagName);
+
   /**
    * Returns an anonymous Element of type aTag,
    * child of aParentContent. If aIsCreatedHidden is true, the class
    * "hidden" is added to the created element. If aAnonClass is not
    * the empty string, it becomes the value of the attribute "_moz_anonclass"
    * @return a Element
    * @param aTag             [IN] desired type of the element to create
    * @param aParentContent   [IN] the parent node of the created anonymous

--- a/editor/libeditor/HTMLEditorCommands.cpp
+++ b/editor/libeditor/HTMLEditorCommands.cpp
@@ -1531,22 +1531,26 @@ InsertTagCommand::DoCommand(const char* 
   if (NS_WARN_IF(!editor)) {
     return NS_ERROR_FAILURE;
   }
   mozilla::HTMLEditor* htmlEditor = editor->AsHTMLEditor();
   if (NS_WARN_IF(!htmlEditor)) {
     return NS_ERROR_FAILURE;
   }
 
-  RefPtr<Element> newElement;
-  nsresult rv = htmlEditor->CreateElementWithDefaults(
-    nsDependentAtomString(mTagName), getter_AddRefs(newElement));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  return htmlEditor->InsertElementAtSelection(newElement, true);
+  RefPtr<Element> newElement =
+    htmlEditor->CreateElementWithDefaults(*mTagName);
+  if (NS_WARN_IF(!newElement)) {
+    return NS_ERROR_FAILURE;
+  }
+  nsresult rv = htmlEditor->InsertElementAtSelection(newElement, true);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
 }
 
 NS_IMETHODIMP
 InsertTagCommand::DoCommandParams(const char *aCommandName,
                                   nsICommandParams *aParams,
                                   nsISupports *refCon)
 {
   NS_ENSURE_ARG_POINTER(refCon);
@@ -1586,32 +1590,42 @@ InsertTagCommand::DoCommandParams(const 
   if (mTagName == nsGkAtoms::a) {
     attributeType.AssignLiteral("href");
   } else if (mTagName == nsGkAtoms::img) {
     attributeType.AssignLiteral("src");
   } else {
     return NS_ERROR_NOT_IMPLEMENTED;
   }
 
-  RefPtr<Element> elem;
-  rv = htmlEditor->CreateElementWithDefaults(nsDependentAtomString(mTagName),
-                                             getter_AddRefs(elem));
-  NS_ENSURE_SUCCESS(rv, rv);
+  RefPtr<Element> newElement =
+    htmlEditor->CreateElementWithDefaults(*mTagName);
+  if (NS_WARN_IF(!newElement)) {
+    return NS_ERROR_FAILURE;
+  }
 
   ErrorResult err;
-  elem->SetAttribute(attributeType, attribute, err);
+  newElement->SetAttribute(attributeType, attribute, err);
   if (NS_WARN_IF(err.Failed())) {
     return err.StealNSResult();
   }
 
   // do actual insertion
   if (mTagName == nsGkAtoms::a) {
-    return htmlEditor->InsertLinkAroundSelection(elem);
+    rv = htmlEditor->InsertLinkAroundSelection(newElement);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    return NS_OK;
   }
-  return htmlEditor->InsertElementAtSelection(elem, true);
+
+  rv = htmlEditor->InsertElementAtSelection(newElement, true);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
 }
 
 NS_IMETHODIMP
 InsertTagCommand::GetCommandStateParams(const char *aCommandName,
                                         nsICommandParams *aParams,
                                         nsISupports *refCon)
 {
   NS_ENSURE_ARG_POINTER(aParams);

--- a/editor/libeditor/HTMLTableEditor.cpp
+++ b/editor/libeditor/HTMLTableEditor.cpp
@@ -104,18 +104,17 @@ HTMLEditor::InsertCell(Element* aCell,
 
   // And the parent and offsets needed to do an insert
   EditorDOMPoint pointToInsert(aCell);
   if (NS_WARN_IF(!pointToInsert.IsSet())) {
     return NS_ERROR_INVALID_ARG;
   }
 
   RefPtr<Element> newCell =
-    CreateElementWithDefaults(aIsHeader ? NS_LITERAL_STRING("th") :
-                                          NS_LITERAL_STRING("tb"));
+    CreateElementWithDefaults(aIsHeader ? *nsGkAtoms::th : *nsGkAtoms::td);
   if (NS_WARN_IF(!newCell)) {
     return NS_ERROR_FAILURE;
   }
 
   //Optional: return new cell created
   if (aNewCell) {
     *aNewCell = do_AddRef(newCell).take();
   }
@@ -197,28 +196,28 @@ HTMLEditor::InsertTableCell(int32_t aNum
   //We control selection resetting after the insert...
   AutoSelectionSetterAfterTableEdit setCaret(*this, table, startRowIndex,
                                              newCellIndex, ePreviousColumn,
                                              false);
   //...so suppress Rules System selection munging
   AutoTransactionsConserveSelection dontChangeSelection(*this);
 
   for (int32_t i = 0; i < aNumber; i++) {
-    RefPtr<Element> newCell;
-    rv = CreateElementWithDefaults(NS_LITERAL_STRING("td"),
-                                   getter_AddRefs(newCell));
-    if (NS_SUCCEEDED(rv) && newCell) {
+    RefPtr<Element> newCell = CreateElementWithDefaults(*nsGkAtoms::td);
+    if (newCell) {
       if (aAfter) {
         cellOffset++;
       }
       rv = InsertNodeWithTransaction(*newCell,
                                      EditorRawDOMPoint(cellParent, cellOffset));
       if (NS_FAILED(rv)) {
         break;
       }
+    } else {
+      rv = NS_ERROR_FAILURE;
     }
   }
   // XXX This is perhaps the result of the last call of
   //     InsertNodeWithTransaction() or CreateElementWithDefaults().
   return rv;
 }
 
 NS_IMETHODIMP
@@ -620,23 +619,26 @@ HTMLEditor::InsertTableRow(int32_t aNumb
 
     // Adjust for when adding past the end
     if (aAfter && startRowIndex >= rowCount) {
       newRowOffset++;
     }
 
     for (int32_t row = 0; row < aNumber; row++) {
       // Create a new row
-      nsCOMPtr<Element> newRow = CreateElementWithDefaults(trStr);
-      NS_ENSURE_TRUE(newRow, NS_ERROR_FAILURE);
+      RefPtr<Element> newRow = CreateElementWithDefaults(*nsGkAtoms::tr);
+      if (NS_WARN_IF(!newRow)) {
+        return NS_ERROR_FAILURE;
+      }
 
       for (int32_t i = 0; i < cellsInRow; i++) {
-        nsCOMPtr<Element> newCell =
-          CreateElementWithDefaults(NS_LITERAL_STRING("td"));
-        NS_ENSURE_TRUE(newCell, NS_ERROR_FAILURE);
+        RefPtr<Element> newCell = CreateElementWithDefaults(*nsGkAtoms::td);
+        if (NS_WARN_IF(!newCell)) {
+          return NS_ERROR_FAILURE;
+        }
 
         // Don't use transaction system yet! (not until entire row is
         // inserted)
         ErrorResult result;
         newRow->AppendChild(*newCell, result);
         if (NS_WARN_IF(result.Failed())) {
           return result.StealNSResult();
         }

--- a/extensions/pref/autoconfig/public/moz.build
+++ b/extensions/pref/autoconfig/public/moz.build
@@ -1,13 +1,12 @@
 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # 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/.
 
 XPIDL_SOURCES += [
-    'nsIAutoConfig.idl',
     'nsIReadConfig.idl',
 ]
 
 XPIDL_MODULE = 'autoconfig'
 

deleted file mode 100644
--- a/extensions/pref/autoconfig/public/nsIAutoConfig.idl
+++ /dev/null
@@ -1,26 +0,0 @@
-/* -*- 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/. */
-
-#include "nsISupports.idl"
-
-
-%{C++
-
-#define NS_AUTOCONFIG_CID\
-  { 0xe036c738,\
-    0x1dd1,\
-    0x11b2,\
-    { 0x93, 0x92, 0x9d, 0x94, 0xaa, 0x74, 0xb0, 0xc5 }\
-  }
- 
-#define NS_AUTOCONFIG_CONTRACTID \
-  "@mozilla.org/autoconfiguration;1" 
-
-%}
-
-[uuid (80DB54AE-13F2-11d5-BE44-00108335A220)]
-interface nsIAutoConfig : nsISupports {
-  attribute string configURL;
-};

--- a/extensions/pref/autoconfig/src/nsAutoConfig.cpp
+++ b/extensions/pref/autoconfig/src/nsAutoConfig.cpp
@@ -28,17 +28,17 @@
 #include "mozilla/Logging.h"
 
 using mozilla::LogLevel;
 
 mozilla::LazyLogModule MCD("MCD");
 
 // nsISupports Implementation
 
-NS_IMPL_ISUPPORTS(nsAutoConfig, nsIAutoConfig, nsITimerCallback, nsIStreamListener,
+NS_IMPL_ISUPPORTS(nsAutoConfig, nsITimerCallback, nsIStreamListener,
                   nsIObserver, nsIRequestObserver, nsISupportsWeakReference,
                   nsINamed)
 
 nsAutoConfig::nsAutoConfig()
 {
 }
 
 nsresult nsAutoConfig::Init()
@@ -58,38 +58,20 @@ nsresult nsAutoConfig::Init()
 
     return rv;
 }
 
 nsAutoConfig::~nsAutoConfig()
 {
 }
 
-// attribute string configURL
-NS_IMETHODIMP nsAutoConfig::GetConfigURL(char **aConfigURL)
+void
+nsAutoConfig::SetConfigURL(const char *aConfigURL)
 {
-    if (!aConfigURL)
-        return NS_ERROR_NULL_POINTER;
-
-    if (mConfigURL.IsEmpty()) {
-        *aConfigURL = nullptr;
-        return NS_OK;
-    }
-
-    *aConfigURL = ToNewCString(mConfigURL);
-    if (!*aConfigURL)
-        return NS_ERROR_OUT_OF_MEMORY;
-    return NS_OK;
-}
-NS_IMETHODIMP nsAutoConfig::SetConfigURL(const char *aConfigURL)
-{
-    if (!aConfigURL)
-        return NS_ERROR_NULL_POINTER;
     mConfigURL.Assign(aConfigURL);
-    return NS_OK;
 }
 
 NS_IMETHODIMP
 nsAutoConfig::OnStartRequest(nsIRequest *request, nsISupports *context)
 {
     return NS_OK;
 }
 

--- a/extensions/pref/autoconfig/src/nsAutoConfig.h
+++ b/extensions/pref/autoconfig/src/nsAutoConfig.h
@@ -1,48 +1,47 @@
 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef nsAutoConfig_h
 #define nsAutoConfig_h
 
-#include "nsIAutoConfig.h"
 #include "nsITimer.h"
 #include "nsIFile.h"
 #include "nsINamed.h"
 #include "nsIObserver.h"
 #include "nsIStreamListener.h"
 #include "nsIPrefService.h"
 #include "nsIPrefBranch.h"
 #include "nsWeakReference.h"
 #include "nsString.h"
 
-class nsAutoConfig : public nsIAutoConfig,
-                     public nsITimerCallback,
-                     public nsIStreamListener,
-                     public nsIObserver,
-                     public nsSupportsWeakReference,
-                     public nsINamed
+class nsAutoConfig final : public nsITimerCallback,
+                           public nsIStreamListener,
+                           public nsIObserver,
+                           public nsSupportsWeakReference,
+                           public nsINamed
 
 {
     public:
 
         NS_DECL_THREADSAFE_ISUPPORTS
-        NS_DECL_NSIAUTOCONFIG
         NS_DECL_NSIREQUESTOBSERVER
         NS_DECL_NSISTREAMLISTENER
         NS_DECL_NSIOBSERVER
         NS_DECL_NSITIMERCALLBACK
         NS_DECL_NSINAMED
 
         nsAutoConfig();
         nsresult Init();
 
+        void SetConfigURL(const char* aConfigURL);
+
     protected:
 
         virtual ~nsAutoConfig();
         nsresult downloadAutoConfig();
         nsresult readOfflineFile();
         nsresult evaluateLocalFile(nsIFile *file);
         nsresult writeFailoverFile();
         nsresult getEmailAddr(nsACString & emailAddr);

--- a/extensions/pref/autoconfig/src/nsConfigFactory.cpp
+++ b/extensions/pref/autoconfig/src/nsConfigFactory.cpp
@@ -1,32 +1,27 @@
 /* -*- Mode: C++; 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/. */
 
 #include "mozilla/ModuleUtils.h"
-#include "nsAutoConfig.h"
 #include "nsReadConfig.h"
 #include "nsIAppStartupNotifier.h"
 
-NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(nsAutoConfig, Init)
 NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(nsReadConfig, Init)
 
-NS_DEFINE_NAMED_CID(NS_AUTOCONFIG_CID);
 NS_DEFINE_NAMED_CID(NS_READCONFIG_CID);
 
 static const mozilla::Module::CIDEntry kAutoConfigCIDs[] = {
-  { &kNS_AUTOCONFIG_CID, false, nullptr, nsAutoConfigConstructor },
   { &kNS_READCONFIG_CID, false, nullptr, nsReadConfigConstructor },
   { nullptr }
 };
 
 static const mozilla::Module::ContractIDEntry kAutoConfigContracts[] = {
-  { NS_AUTOCONFIG_CONTRACTID, &kNS_AUTOCONFIG_CID },
   { NS_READCONFIG_CONTRACTID, &kNS_READCONFIG_CID },
   { nullptr }
 };
 
 static const mozilla::Module::CategoryEntry kAutoConfigCategories[] = {
   { "pref-config-startup", "ReadConfig Module", NS_READCONFIG_CONTRACTID },
   { nullptr }
 };

--- a/extensions/pref/autoconfig/src/nsReadConfig.cpp
+++ b/extensions/pref/autoconfig/src/nsReadConfig.cpp
@@ -5,17 +5,16 @@
 
 #include "nsReadConfig.h"
 #include "nsJSConfigTriggers.h"
 
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsIAppStartup.h"
 #include "nsContentUtils.h"
 #include "nsDirectoryServiceDefs.h"
-#include "nsIAutoConfig.h"
 #include "nsIComponentManager.h"
 #include "nsIFile.h"
 #include "nsIObserverService.h"
 #include "nsIPrefBranch.h"
 #include "nsIPrefService.h"
 #include "nsIPromptService.h"
 #include "nsIServiceManager.h"
 #include "nsIStringBundle.h"
@@ -228,24 +227,24 @@ nsresult nsReadConfig::readConfigFile()
     }
 
     // get the value of the autoconfig url
     nsAutoCString urlName;
     rv = prefBranch->GetCharPref("autoadmin.global_config_url", urlName);
     if (NS_SUCCEEDED(rv) && !urlName.IsEmpty()) {
 
         // Instantiating nsAutoConfig object if the pref is present
-        mAutoConfig = do_CreateInstance(NS_AUTOCONFIG_CONTRACTID, &rv);
-        if (NS_FAILED(rv))
-            return NS_ERROR_OUT_OF_MEMORY;
+        mAutoConfig = new nsAutoConfig();
 
-        rv = mAutoConfig->SetConfigURL(urlName.get());
-        if (NS_FAILED(rv))
-            return NS_ERROR_FAILURE;
+        rv = mAutoConfig->Init();
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+            return rv;
+        }
 
+        mAutoConfig->SetConfigURL(urlName.get());
     }
 
     return NS_OK;
 } // ReadConfigFile
 
 
 nsresult nsReadConfig::openAndEvaluateJSFile(const char *aFileName, int32_t obscureValue,
                                              bool isEncoded,

--- a/extensions/pref/autoconfig/src/nsReadConfig.h
+++ b/extensions/pref/autoconfig/src/nsReadConfig.h
@@ -1,24 +1,24 @@
 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef nsReadConfig_h
 #define nsReadConfig_h
 
-#include "nsCOMPtr.h"
+#include "mozilla/RefPtr.h"
 #include "nsIReadConfig.h"
-#include "nsIAutoConfig.h"
+#include "nsAutoConfig.h"
 #include "nsIObserver.h"
 
 
-class nsReadConfig : public nsIReadConfig,
-                     public nsIObserver
+class nsReadConfig final : public nsIReadConfig,
+                           public nsIObserver
 {
 
     public:
 
         NS_DECL_THREADSAFE_ISUPPORTS
         NS_DECL_NSIREADCONFIG
         NS_DECL_NSIOBSERVER
 
@@ -30,12 +30,12 @@ class nsReadConfig : public nsIReadConfi
 
         virtual ~nsReadConfig();
 
         nsresult readConfigFile();
         nsresult openAndEvaluateJSFile(const char *aFileName, int32_t obscureValue,
                                         bool isEncoded, bool isBinDir);
         bool mRead;
 private:
-        nsCOMPtr<nsIAutoConfig> mAutoConfig;
+        RefPtr<nsAutoConfig> mAutoConfig;
 };
 
 #endif

--- a/js/src/frontend/DoWhileEmitter.cpp
+++ b/js/src/frontend/DoWhileEmitter.cpp
@@ -26,23 +26,22 @@ DoWhileEmitter::emitBody(const Maybe<uin
     MOZ_ASSERT(state_ == State::Start);
 
     // Ensure that the column of the 'do' is set properly.
     if (doPos) {
         if (!bce_->updateSourceCoordNotes(*doPos))
             return false;
     }
 
-    // Emit an annotated nop so IonBuilder can recognize the 'do' loop.
-    if (!bce_->newSrcNote(SRC_WHILE, &noteIndex_))
-        return false;
+    // We need a nop here to make it possible to set a breakpoint on `do`.
     if (!bce_->emit1(JSOP_NOP))
         return false;
 
-    if (!bce_->newSrcNote(SRC_WHILE, &noteIndex2_))
+    // Emit an annotated nop so IonBuilder can recognize the 'do' loop.
+    if (!bce_->newSrcNote3(SRC_DO_WHILE, 0, 0, &noteIndex_))
         return false;
 
     loopInfo_.emplace(bce_, StatementKind::DoLoop);
 
     if (!loopInfo_->emitLoopHead(bce_, bodyPos))
         return false;
 
     if (!loopInfo_->emitLoopEntry(bce_, Nothing()))
@@ -79,28 +78,23 @@ DoWhileEmitter::emitEnd()
     if (!bce_->tryNoteList.append(JSTRY_LOOP, bce_->stackDepth, loopInfo_->headOffset(),
                                   loopInfo_->breakTargetOffset()))
     {
         return false;
     }
 
     // Update the annotations with the update and back edge positions, for
     // IonBuilder.
-    //
-    // Be careful: We must set noteIndex2_ before_ noteIndex in case the
-    // noteIndex_ note gets bigger.  Otherwise noteIndex2_ can point wrong
-    // position.
-    if (!bce_->setSrcNoteOffset(noteIndex2_, SrcNote::DoWhile2::BackJumpOffset,
-                                loopInfo_->loopEndOffsetFromLoopHead()))
+    if (!bce_->setSrcNoteOffset(noteIndex_, SrcNote::DoWhile::CondOffset,
+                                loopInfo_->continueTargetOffsetFromLoopHead()))
     {
         return false;
     }
-    // +1 for NOP in emitBody.
-    if (!bce_->setSrcNoteOffset(noteIndex_, SrcNote::DoWhile1::CondOffset,
-                                loopInfo_->continueTargetOffsetFromLoopHead() + 1))
+    if (!bce_->setSrcNoteOffset(noteIndex_, SrcNote::DoWhile::BackJumpOffset,
+                                loopInfo_->loopEndOffsetFromLoopHead()))
     {
         return false;
     }
 
     if (!loopInfo_->patchBreaksAndContinues(bce_))
         return false;
 
     loopInfo_.reset();