diff --git a/.eslintignore b/.eslintignore
index 171db4ff9428..fded29d8a802 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -167,7 +167,6 @@ dom/base/test/unit/test_serializers_entities*.js
 dom/base/test/unit_ipc/**
 dom/base/test/jsmodules/**
 dom/bindings/**
-dom/browser-element/**
 dom/canvas/**
 dom/encoding/**
 dom/events/**
diff --git a/dom/browser-element/BrowserElementChild.js b/dom/browser-element/BrowserElementChild.js
index 796bbde38f2f..dc1c1c631379 100644
--- a/dom/browser-element/BrowserElementChild.js
+++ b/dom/browser-element/BrowserElementChild.js
@@ -2,6 +2,9 @@
  * 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/. */
 
+/* eslint-env mozilla/frame-script */
+/* global api, CopyPasteAssistent */
+
 "use strict";
 
 var {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
diff --git a/dom/browser-element/BrowserElementChildPreload.js b/dom/browser-element/BrowserElementChildPreload.js
index cfa62571b5e4..ec74b9fe99dd 100644
--- a/dom/browser-element/BrowserElementChildPreload.js
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -4,6 +4,8 @@
 
 "use strict";
 
+/* eslint-env mozilla/frame-script */
+
 function debug(msg) {
   // dump("BrowserElementChildPreload - " + msg + "\n");
 }
@@ -40,7 +42,7 @@ function sendSyncMsg(msg, data) {
   // Ensure that we don't send any messages before BrowserElementChild.js
   // finishes loading.
   if (!BrowserElementIsReady) {
-    return;
+    return undefined;
   }
 
   if (!data) {
@@ -160,10 +162,8 @@ BrowserElementChild.prototype = {
 
     addMessageListener("browser-element-api:call", this);
 
-    let els = Cc["@mozilla.org/eventlistenerservice;1"]
-                .getService(Ci.nsIEventListenerService);
     LISTENED_SYSTEM_EVENTS.forEach(event => {
-      els.addSystemEventListener(global, event.type, this, event.useCapture);
+      Services.els.addSystemEventListener(global, event.type, this, event.useCapture);
     });
 
     OBSERVED_EVENTS.forEach((aTopic) => {
@@ -192,10 +192,8 @@ BrowserElementChild.prototype = {
 
     removeMessageListener("browser-element-api:call", this);
 
-    let els = Cc["@mozilla.org/eventlistenerservice;1"]
-                .getService(Ci.nsIEventListenerService);
     LISTENED_SYSTEM_EVENTS.forEach(event => {
-      els.removeSystemEventListener(global, event.type, this, event.useCapture);
+      Services.els.removeSystemEventListener(global, event.type, this, event.useCapture);
     });
 
     OBSERVED_EVENTS.forEach((aTopic) => {
@@ -281,6 +279,7 @@ BrowserElementChild.prototype = {
     if (message.data.msg_name in mmCalls) {
       return mmCalls[message.data.msg_name].apply(self, arguments);
     }
+    return undefined;
   },
 
   _paintFrozenTimer: null,
@@ -363,6 +362,7 @@ BrowserElementChild.prototype = {
         args.promptType == "custom-prompt") {
       return returnValue;
     }
+    return undefined;
   },
 
   /**
@@ -379,7 +379,7 @@ BrowserElementChild.prototype = {
       // I have no idea what waiting for a result means when there's no inner
       // window, so let's just bail.
       debug("_waitForResult: No inner window. Bailing.");
-      return;
+      return undefined;
     }
 
     this._windowIDDict[outerWindowID] = Cu.getWeakReference(win);
@@ -902,7 +902,7 @@ BrowserElementChild.prototype = {
     if (menu) {
       this._maybeCopyAttribute(menu, menuObj, "label");
 
-      for (var i = 0, child; child = menu.children[i++];) {
+      for (var i = 0, child; (child = menu.children[i++]);) {
         if (child.nodeName === "MENU") {
           menuObj.items.push(this._buildMenuObj(child, idPrefix + i + "_", false));
         } else if (child.nodeName === "MENUITEM") {
@@ -1026,8 +1026,7 @@ BrowserElementChild.prototype = {
       }
 
       // Remove password from uri.
-      location = Cc["@mozilla.org/docshell/urifixup;1"]
-        .getService(Ci.nsIURIFixup).createExposableURI(location);
+      location = Services.uriFixup.createExposableURI(location);
 
       var webNav = docShell.QueryInterface(Ci.nsIWebNavigation);
 
@@ -1036,6 +1035,7 @@ BrowserElementChild.prototype = {
                                        canGoForward: webNav.canGoForward });
     },
 
+    // eslint-disable-next-line complexity
     onStateChange(webProgress, request, stateFlags, status) {
       if (webProgress != docShell) {
         return;
diff --git a/dom/browser-element/BrowserElementCopyPaste.js b/dom/browser-element/BrowserElementCopyPaste.js
index d40d8a84566c..a9d985d1fc11 100644
--- a/dom/browser-element/BrowserElementCopyPaste.js
+++ b/dom/browser-element/BrowserElementCopyPaste.js
@@ -6,6 +6,14 @@
 
 "use strict";
 
+/*
+global addMessageListener
+global removeMessageListener
+global docShell
+global content
+global sendAsyncMsg
+*/
+
 function debug(msg) {
   // dump("BrowserElementCopyPaste - " + msg + "\n");
 }
@@ -71,7 +79,7 @@ var CopyPasteAssistent = {
     e.stopPropagation();
 
     let boundingClientRect = e.boundingClientRect;
-    let canPaste = this._isCommandEnabled("paste");
+    this._isCommandEnabled("paste");
     let zoomFactor = content.innerWidth == 0 ? 1 : content.screen.width / content.innerWidth;
 
     let detail = {
diff --git a/dom/browser-element/BrowserElementParent.jsm b/dom/browser-element/BrowserElementParent.jsm
index 75062e8866d8..54642352a5bc 100644
--- a/dom/browser-element/BrowserElementParent.jsm
+++ b/dom/browser-element/BrowserElementParent.jsm
@@ -16,14 +16,6 @@ function debug(msg) {
   // dump("BrowserElementParent - " + msg + "\n");
 }
 
-function getIntPref(prefName, def) {
-  try {
-    return Services.prefs.getIntPref(prefName);
-  } catch (err) {
-    return def;
-  }
-}
-
 function handleWindowEvent(e) {
   if (this._browserElementParents) {
     let beps = ChromeUtils.nondeterministicGetWeakMapKeys(this._browserElementParents);
@@ -96,11 +88,9 @@ BrowserElementParent.prototype = {
       this._window._browserElementParents = new WeakMap();
       let handler = handleWindowEvent.bind(this._window);
       let windowEvents = ["visibilitychange", "fullscreenchange"];
-      let els = Cc["@mozilla.org/eventlistenerservice;1"]
-                  .getService(Ci.nsIEventListenerService);
       for (let event of windowEvents) {
-        els.addSystemEventListener(this._window, event, handler,
-                                   /* useCapture = */ true);
+        Services.els.addSystemEventListener(this._window, event, handler,
+                                            /* useCapture = */ true);
       }
     }
 
@@ -138,7 +128,7 @@ BrowserElementParent.prototype = {
 
   receiveMessage(aMsg) {
     if (!this._isAlive()) {
-      return;
+      return undefined;
     }
 
     // Messages we receive are handed to functions which take a (data) argument,
@@ -184,6 +174,7 @@ BrowserElementParent.prototype = {
     } else if (aMsg.data.msg_name in mmSecuritySensitiveCalls) {
       return mmSecuritySensitiveCalls[aMsg.data.msg_name].apply(this, arguments);
     }
+    return undefined;
   },
 
   _removeMessageListener() {
@@ -210,7 +201,6 @@ BrowserElementParent.prototype = {
 
   promptAuth(authDetail, callback) {
     let evt;
-    let self = this;
     let callbackCalled = false;
     let cancelCallback = function() {
       if (!callbackCalled) {
diff --git a/dom/browser-element/BrowserElementPromptService.jsm b/dom/browser-element/BrowserElementPromptService.jsm
index ab1f44bab887..95a880ab05f5 100644
--- a/dom/browser-element/BrowserElementPromptService.jsm
+++ b/dom/browser-element/BrowserElementPromptService.jsm
@@ -294,8 +294,6 @@ BrowserElementAuthPrompt.prototype = {
       return;
 
     let prompt = this._asyncPrompts[hashKey];
-    let [hostname, httpRealm] = this._getAuthTarget(prompt.channel,
-                                                    prompt.authInfo);
 
     this._asyncPromptInProgress.set(prompt.browserElementParent, true);
     prompt.inProgress = true;
@@ -570,16 +568,14 @@ var BrowserElementPromptService = {
 
     // If the pref is disabled, do nothing except wait for the pref to change.
     if (!this._browserFramesPrefEnabled()) {
-      var prefs = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
-      prefs.addObserver(BROWSER_FRAMES_ENABLED_PREF, this, /* ownsWeak = */ true);
+      Services.prefs.addObserver(BROWSER_FRAMES_ENABLED_PREF, this, /* ownsWeak = */ true);
       return;
     }
 
     this._initialized = true;
     this._browserElementParentMap = new WeakMap();
 
-    var os = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
-    os.addObserver(this, "outer-window-destroyed", /* ownsWeak = */ true);
+    Services.obs.addObserver(this, "outer-window-destroyed", /* ownsWeak = */ true);
 
     // Wrap the existing @mozilla.org/prompter;1 implementation.
     var contractID = "@mozilla.org/prompter;1";
@@ -644,12 +640,7 @@ var BrowserElementPromptService = {
   },
 
   _browserFramesPrefEnabled() {
-    var prefs = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
-    try {
-      return prefs.getBoolPref(BROWSER_FRAMES_ENABLED_PREF);
-    } catch (e) {
-      return false;
-    }
+    return Services.prefs.getBoolPref(BROWSER_FRAMES_ENABLED_PREF, false);
   },
 
   observe(subject, topic, data) {
diff --git a/dom/browser-element/mochitest/async.js b/dom/browser-element/mochitest/async.js
index e16513556f67..8afa3ab7664c 100644
--- a/dom/browser-element/mochitest/async.js
+++ b/dom/browser-element/mochitest/async.js
@@ -69,7 +69,7 @@
               }
             ).catch(err => reject(err));
           }
-          step(gen.next(value));
+          return step(gen.next(value));
         }
       });
     };
diff --git a/dom/browser-element/mochitest/browserElement_Alert.js b/dom/browser-element/mochitest/browserElement_Alert.js
index 846d1762adf8..9603ba69b2bc 100644
--- a/dom/browser-element/mochitest/browserElement_Alert.js
+++ b/dom/browser-element/mochitest/browserElement_Alert.js
@@ -4,6 +4,8 @@
 // Test that alert works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_AlertInFrame.js b/dom/browser-element/mochitest/browserElement_AlertInFrame.js
index 5a2c3beb431f..77a9537a4167 100644
--- a/dom/browser-element/mochitest/browserElement_AlertInFrame.js
+++ b/dom/browser-element/mochitest/browserElement_AlertInFrame.js
@@ -4,6 +4,8 @@
 // Test that alert works from inside an <iframe> inside an <iframe mozbrowser>.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_Auth.js b/dom/browser-element/mochitest/browserElement_Auth.js
index 96c331317ebd..8ffaf71f622b 100644
--- a/dom/browser-element/mochitest/browserElement_Auth.js
+++ b/dom/browser-element/mochitest/browserElement_Auth.js
@@ -4,6 +4,8 @@
 // Test that auth prompt works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -37,9 +39,9 @@ function testHttpAuthCancel(e) {
   // Will cancel authentication, but prompt should not be shown again. Instead,
   // we will be led to fail message
   iframe.addEventListener("mozbrowserusernameandpasswordrequired", testFail);
-  iframe.addEventListener("mozbrowsertitlechange", function(e) {
+  iframe.addEventListener("mozbrowsertitlechange", function(f) {
     iframe.removeEventListener("mozbrowserusernameandpasswordrequired", testFail);
-    is(e.detail, "http auth failed", "expected authentication to fail");
+    is(f.detail, "http auth failed", "expected authentication to fail");
     iframe.addEventListener("mozbrowserusernameandpasswordrequired", testHttpAuth);
     SimpleTest.executeSoon(function() {
       // Use absolute path because we need to specify host.
@@ -65,9 +67,9 @@ function testHttpAuth(e) {
   // Will authenticate with correct password, prompt should not be
   // called again.
   iframe.addEventListener("mozbrowserusernameandpasswordrequired", testFail);
-  iframe.addEventListener("mozbrowsertitlechange", function(e) {
+  iframe.addEventListener("mozbrowsertitlechange", function(f) {
     iframe.removeEventListener("mozbrowserusernameandpasswordrequired", testFail);
-    is(e.detail, "http auth success", "expect authentication to succeed");
+    is(f.detail, "http auth success", "expect authentication to succeed");
     SimpleTest.executeSoon(testProxyAuth);
   }, {once: true});
 
@@ -84,7 +86,7 @@ function testHttpAuth(e) {
   });
 }
 
-function testProxyAuth(e) {
+function testProxyAuth() {
   // The testingSJS simulates the 407 proxy authentication required response
   // for proxy server, which will trigger the browser element to send prompt
   // event with proxy infomation.
@@ -94,9 +96,9 @@ function testProxyAuth(e) {
   function onUserNameAndPasswordRequired(e) {
     iframe.removeEventListener("mozbrowserusernameandpasswordrequired",
                                onUserNameAndPasswordRequired);
-    iframe.addEventListener("mozbrowsertitlechange", function(e) {
+    iframe.addEventListener("mozbrowsertitlechange", function(event) {
       iframe.removeEventListener("mozbrowserusernameandpasswordrequired", testFail);
-      is(e.detail, "http auth success", "expect authentication to succeed");
+      is(event.detail, "http auth success", "expect authentication to succeed");
       SimpleTest.executeSoon(testAuthJarNoInterfere);
     }, {once: true});
 
@@ -149,12 +151,10 @@ function testProxyAuth(e) {
 }
 
 function testAuthJarNoInterfere(e) {
-  var authMgr = SpecialPowers.Cc["@mozilla.org/network/http-auth-manager;1"]
+  let authMgr = SpecialPowers.Cc["@mozilla.org/network/http-auth-manager;1"]
     .getService(SpecialPowers.Ci.nsIHttpAuthManager);
-  var secMan = SpecialPowers.Cc["@mozilla.org/scriptsecuritymanager;1"]
-               .getService(SpecialPowers.Ci.nsIScriptSecurityManager);
-  var ioService = SpecialPowers.Cc["@mozilla.org/network/io-service;1"]
-                  .getService(SpecialPowers.Ci.nsIIOService);
+  let secMan = SpecialPowers.Services.scriptSecurityManager;
+  let ioService = SpecialPowers.Services.io;
   var uri = ioService.newURI("http://test/tests/dom/browser-element/mochitest/file_http_401_response.sjs");
 
   // Set a bunch of auth data that should not conflict with the correct auth data already
@@ -177,9 +177,9 @@ function testAuthJarNoInterfere(e) {
   // Will authenticate with correct password, prompt should not be
   // called again.
   iframe.addEventListener("mozbrowserusernameandpasswordrequired", testFail);
-  iframe.addEventListener("mozbrowsertitlechange", function(e) {
+  iframe.addEventListener("mozbrowsertitlechange", function(f) {
     iframe.removeEventListener("mozbrowserusernameandpasswordrequired", testFail);
-    is(e.detail, "http auth success", "expected authentication success");
+    is(f.detail, "http auth success", "expected authentication success");
     SimpleTest.executeSoon(testAuthJarInterfere);
   }, {once: true});
 
@@ -189,12 +189,10 @@ function testAuthJarNoInterfere(e) {
 }
 
 function testAuthJarInterfere(e) {
-  var authMgr = SpecialPowers.Cc["@mozilla.org/network/http-auth-manager;1"]
+  let authMgr = SpecialPowers.Cc["@mozilla.org/network/http-auth-manager;1"]
     .getService(SpecialPowers.Ci.nsIHttpAuthManager);
-  var secMan = SpecialPowers.Cc["@mozilla.org/scriptsecuritymanager;1"]
-               .getService(SpecialPowers.Ci.nsIScriptSecurityManager);
-  var ioService = SpecialPowers.Cc["@mozilla.org/network/io-service;1"]
-                  .getService(SpecialPowers.Ci.nsIIOService);
+  let secMan = SpecialPowers.Services.scriptSecurityManager;
+  let ioService = SpecialPowers.Services.io;
   var uri = ioService.newURI("http://test/tests/dom/browser-element/mochitest/file_http_401_response.sjs");
 
   // Set some auth data that should overwrite the successful stored details.
@@ -211,7 +209,7 @@ function testAuthJarInterfere(e) {
   }
   iframe.addEventListener("mozbrowserusernameandpasswordrequired",
                           onUserNameAndPasswordRequired);
-  iframe.addEventListener("mozbrowsertitlechange", function(e) {
+  iframe.addEventListener("mozbrowsertitlechange", function(f) {
     iframe.removeEventListener("mozbrowserusernameandpasswordrequired",
                                onUserNameAndPasswordRequired);
     ok(gotusernamepasswordrequired,
@@ -226,13 +224,11 @@ function testAuthJarInterfere(e) {
 
 function testFinish() {
   // Clear login information stored in password manager.
-  var authMgr = SpecialPowers.Cc["@mozilla.org/network/http-auth-manager;1"]
+  let authMgr = SpecialPowers.Cc["@mozilla.org/network/http-auth-manager;1"]
     .getService(SpecialPowers.Ci.nsIHttpAuthManager);
   authMgr.clearAll();
 
-  var pwmgr = SpecialPowers.Cc["@mozilla.org/login-manager;1"]
-    .getService(SpecialPowers.Ci.nsILoginManager);
-  pwmgr.removeAllLogins();
+  SpecialPowers.Services.logins.removeAllLogins();
 
   SimpleTest.finish();
 }
diff --git a/dom/browser-element/mochitest/browserElement_BackForward.js b/dom/browser-element/mochitest/browserElement_BackForward.js
index 5d32105bd1a2..8c825a0a0f72 100644
--- a/dom/browser-element/mochitest/browserElement_BackForward.js
+++ b/dom/browser-element/mochitest/browserElement_BackForward.js
@@ -5,6 +5,9 @@
 // <iframe mozbrowser>.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 
diff --git a/dom/browser-element/mochitest/browserElement_BrowserWindowNamespace.js b/dom/browser-element/mochitest/browserElement_BrowserWindowNamespace.js
index b5bcab6665de..b18171e1685b 100644
--- a/dom/browser-element/mochitest/browserElement_BrowserWindowNamespace.js
+++ b/dom/browser-element/mochitest/browserElement_BrowserWindowNamespace.js
@@ -7,6 +7,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -23,12 +25,12 @@ function runTest() {
     ok(true, "Got first mozbrowseropenwindow event.");
     document.body.appendChild(e.detail.frameElement);
 
-    e.detail.frameElement.addEventListener("mozbrowserlocationchange", function(e) {
-      if (e.detail.url == "http://example.com/#2") {
+    e.detail.frameElement.addEventListener("mozbrowserlocationchange", function(f) {
+      if (f.detail.url == "http://example.com/#2") {
         ok(true, "Got locationchange to http://example.com/#2");
         SimpleTest.finish();
       } else {
-        ok(true, "Got locationchange to " + e.detail.url);
+        ok(true, "Got locationchange to " + f.detail.url);
       }
     });
 
@@ -40,7 +42,7 @@ function runTest() {
       SpecialPowers.wrap(iframe2).presetOpenerWindow(iframe1.contentWindow);
       iframe2.setAttribute("mozbrowser", "true");
 
-      iframe2.addEventListener("mozbrowseropenwindow", function(e) {
+      iframe2.addEventListener("mozbrowseropenwindow", function(f) {
         ok(false, "Got second mozbrowseropenwindow event.");
       });
 
diff --git a/dom/browser-element/mochitest/browserElement_BrowserWindowResize.js b/dom/browser-element/mochitest/browserElement_BrowserWindowResize.js
index 62d9803dd04a..d58b9b3be03a 100644
--- a/dom/browser-element/mochitest/browserElement_BrowserWindowResize.js
+++ b/dom/browser-element/mochitest/browserElement_BrowserWindowResize.js
@@ -4,6 +4,8 @@
 // Bug 891763 - Test the mozbrowserresize event
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_Close.js b/dom/browser-element/mochitest/browserElement_Close.js
index a4f07dcf320f..270057de843d 100644
--- a/dom/browser-element/mochitest/browserElement_Close.js
+++ b/dom/browser-element/mochitest/browserElement_Close.js
@@ -4,6 +4,8 @@
 // Test that window.close() works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -19,7 +21,7 @@ function runTest() {
     SimpleTest.finish();
   });
 
-  iframe.src = "data:text/html,<html><body><script>window.close()</scr" + "ipt></body></html>";
+  iframe.src = "data:text/html,<html><body><script>window.close()</script></body></html>";
 }
 
 addEventListener("testready", runTest);
diff --git a/dom/browser-element/mochitest/browserElement_CloseFromOpener.js b/dom/browser-element/mochitest/browserElement_CloseFromOpener.js
index b020d60e7182..33116cbfd3bb 100644
--- a/dom/browser-element/mochitest/browserElement_CloseFromOpener.js
+++ b/dom/browser-element/mochitest/browserElement_CloseFromOpener.js
@@ -4,6 +4,8 @@
 // Bug 764718 - Test that window.close() works from the opener window.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -16,7 +18,7 @@ function runTest() {
     ok(true, "got openwindow event.");
     document.body.appendChild(e.detail.frameElement);
 
-    e.detail.frameElement.addEventListener("mozbrowserclose", function(e) {
+    e.detail.frameElement.addEventListener("mozbrowserclose", function(f) {
       ok(true, "got mozbrowserclose event.");
       SimpleTest.finish();
     });
diff --git a/dom/browser-element/mochitest/browserElement_ContextmenuEvents.js b/dom/browser-element/mochitest/browserElement_ContextmenuEvents.js
index 75a52d303973..b4f4053656ea 100644
--- a/dom/browser-element/mochitest/browserElement_ContextmenuEvents.js
+++ b/dom/browser-element/mochitest/browserElement_ContextmenuEvents.js
@@ -1,5 +1,8 @@
 "use strict";
 
+/* global browserElementTestHelpers */
+/* eslint-env mozilla/frame-script */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.setClipboardPlainTextOnlyPref(false);
diff --git a/dom/browser-element/mochitest/browserElement_CookiesNotThirdParty.js b/dom/browser-element/mochitest/browserElement_CookiesNotThirdParty.js
index 3130e352891d..892ac1292309 100644
--- a/dom/browser-element/mochitest/browserElement_CookiesNotThirdParty.js
+++ b/dom/browser-element/mochitest/browserElement_CookiesNotThirdParty.js
@@ -5,6 +5,8 @@
 // third-party.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_CopyPaste.js b/dom/browser-element/mochitest/browserElement_CopyPaste.js
index 50df427e8468..3d6e0570596f 100644
--- a/dom/browser-element/mochitest/browserElement_CopyPaste.js
+++ b/dom/browser-element/mochitest/browserElement_CopyPaste.js
@@ -4,13 +4,14 @@
 // Test that "cut, copy, paste, selectall" and caretstatechanged event works from inside an <iframe mozbrowser>.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 SimpleTest.requestFlakyTimeout("untriaged");
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.setupAccessibleCaretPref();
 browserElementTestHelpers.addPermission();
 browserElementTestHelpers.allowTopLevelDataURINavigation();
-const { Services } = SpecialPowers.Cu.import("resource://gre/modules/Services.jsm");
 
 var gTextarea = null;
 var mm;
@@ -72,9 +73,9 @@ function runTest() {
       iframeInner.setAttribute("mozbrowser", true);
       iframeInner.setAttribute("remote", "false");
       contentDoc.body.appendChild(iframeInner);
-      iframeInner.addEventListener("mozbrowserloadend", function(e) {
+      iframeInner.addEventListener("mozbrowserloadend", function(f) {
         mm = SpecialPowers.getBrowserFrameMessageManager(iframeInner);
-        dispatchTest(e);
+        dispatchTest(f);
       }, {once: true});
     } else {
       iframeInner = iframeOuter;
@@ -96,9 +97,9 @@ function doCommand(cmd) {
 }
 
 function dispatchTest(e) {
-  iframeInner.addEventListener("mozbrowserloadend", function(e) {
+  iframeInner.addEventListener("mozbrowserloadend", function(f) {
     iframeInner.focus();
-    SimpleTest.executeSoon(function() { testSelectAll(e); });
+    SimpleTest.executeSoon(function() { testSelectAll(f); });
   }, {once: true});
 
   switch (state) {
@@ -180,21 +181,20 @@ function dispatchTest(e) {
 }
 
 function isChildProcess() {
-  return SpecialPowers.Cc["@mozilla.org/xre/app-info;1"]
-                         .getService(SpecialPowers.Ci.nsIXULRuntime)
-                         .processType != SpecialPowers.Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT;
+  return SpecialPowers.Services.appinfo
+                      .processType != SpecialPowers.Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT;
 }
 
 function testSelectAll(e) {
   // Skip mozbrowser test if we're at child process.
   if (!isChildProcess()) {
     let eventName = "mozbrowsercaretstatechanged";
-    iframeOuter.addEventListener(eventName, function(e) {
+    iframeOuter.addEventListener(eventName, function(f) {
       ok(true, "got mozbrowsercaretstatechanged event." + stateMeaning);
-      ok(e.detail, "event.detail is not null." + stateMeaning);
-      ok(e.detail.width != 0, "event.detail.width is not zero" + stateMeaning);
-      ok(e.detail.height != 0, "event.detail.height is not zero" + stateMeaning);
-      SimpleTest.executeSoon(function() { testCopy1(e); });
+      ok(f.detail, "event.detail is not null." + stateMeaning);
+      ok(f.detail.width != 0, "event.detail.width is not zero" + stateMeaning);
+      ok(f.detail.height != 0, "event.detail.height is not zero" + stateMeaning);
+      SimpleTest.executeSoon(function() { testCopy1(f); });
     }, {capture: true, once: true});
   }
 
@@ -336,4 +336,3 @@ addEventListener("testready", function() {
     {type: "browser", allow: 1, context},
   ], runTest);
 });
-
diff --git a/dom/browser-element/mochitest/browserElement_DataURI.js b/dom/browser-element/mochitest/browserElement_DataURI.js
index b88282f43fcd..beebf0b6e5a3 100644
--- a/dom/browser-element/mochitest/browserElement_DataURI.js
+++ b/dom/browser-element/mochitest/browserElement_DataURI.js
@@ -4,6 +4,9 @@
 // Test that data: URIs work with mozbrowserlocationchange events.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_DataURILoad.js b/dom/browser-element/mochitest/browserElement_DataURILoad.js
index 212eeb99c226..2fe0cf20574e 100644
--- a/dom/browser-element/mochitest/browserElement_DataURILoad.js
+++ b/dom/browser-element/mochitest/browserElement_DataURILoad.js
@@ -2,6 +2,9 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 SimpleTest.requestFlakyTimeout("testing mozbrowser data: navigation is blocked");
 
diff --git a/dom/browser-element/mochitest/browserElement_DocumentFirstPaint.js b/dom/browser-element/mochitest/browserElement_DocumentFirstPaint.js
index 8c9e90af5adb..169ec928c1e1 100644
--- a/dom/browser-element/mochitest/browserElement_DocumentFirstPaint.js
+++ b/dom/browser-element/mochitest/browserElement_DocumentFirstPaint.js
@@ -4,6 +4,8 @@
 // Bug 829486 - Add mozdocumentbrowserfirstpaint event.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 
diff --git a/dom/browser-element/mochitest/browserElement_ErrorSecurity.js b/dom/browser-element/mochitest/browserElement_ErrorSecurity.js
index 56cbb758e93c..989f4e721293 100644
--- a/dom/browser-element/mochitest/browserElement_ErrorSecurity.js
+++ b/dom/browser-element/mochitest/browserElement_ErrorSecurity.js
@@ -5,6 +5,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_ExposableURI.js b/dom/browser-element/mochitest/browserElement_ExposableURI.js
index 47e2b0a1e4e6..da82f020406b 100644
--- a/dom/browser-element/mochitest/browserElement_ExposableURI.js
+++ b/dom/browser-element/mochitest/browserElement_ExposableURI.js
@@ -5,6 +5,9 @@
 // "unexposable" parts before sending them in the locationchange event.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_FirstPaint.js b/dom/browser-element/mochitest/browserElement_FirstPaint.js
index c835781733d5..57317d83e22e 100644
--- a/dom/browser-element/mochitest/browserElement_FirstPaint.js
+++ b/dom/browser-element/mochitest/browserElement_FirstPaint.js
@@ -4,6 +4,8 @@
 // Bug 787378 - Add mozbrowserfirstpaint event.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_ForwardName.js b/dom/browser-element/mochitest/browserElement_ForwardName.js
index fc1f6b9a4b19..a65a9f102b7f 100644
--- a/dom/browser-element/mochitest/browserElement_ForwardName.js
+++ b/dom/browser-element/mochitest/browserElement_ForwardName.js
@@ -6,6 +6,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_FrameWrongURI.js b/dom/browser-element/mochitest/browserElement_FrameWrongURI.js
index 27c789e81729..65aa31a14092 100644
--- a/dom/browser-element/mochitest/browserElement_FrameWrongURI.js
+++ b/dom/browser-element/mochitest/browserElement_FrameWrongURI.js
@@ -4,6 +4,9 @@
 // Bug 804446 - Test that window.open(javascript:..) works with <iframe mozbrowser>.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_Iconchange.js b/dom/browser-element/mochitest/browserElement_Iconchange.js
index b166ad6d5e24..6eedd68b99f4 100644
--- a/dom/browser-element/mochitest/browserElement_Iconchange.js
+++ b/dom/browser-element/mochitest/browserElement_Iconchange.js
@@ -4,6 +4,8 @@
 // Test that the onmozbrowsericonchange event works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_LoadEvents.js b/dom/browser-element/mochitest/browserElement_LoadEvents.js
index 5587abb40086..1845681790a1 100644
--- a/dom/browser-element/mochitest/browserElement_LoadEvents.js
+++ b/dom/browser-element/mochitest/browserElement_LoadEvents.js
@@ -5,6 +5,9 @@
 // events when this page is in the whitelist.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_Metachange.js b/dom/browser-element/mochitest/browserElement_Metachange.js
index 5acb21d5866a..88c1bf9d0917 100644
--- a/dom/browser-element/mochitest/browserElement_Metachange.js
+++ b/dom/browser-element/mochitest/browserElement_Metachange.js
@@ -4,6 +4,8 @@
 // Test that the onmozbrowsermetachange event works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_OpenNamed.js b/dom/browser-element/mochitest/browserElement_OpenNamed.js
index 82300e8deccd..41d7482d12d1 100644
--- a/dom/browser-element/mochitest/browserElement_OpenNamed.js
+++ b/dom/browser-element/mochitest/browserElement_OpenNamed.js
@@ -5,6 +5,9 @@
 // with the same name, we get only one mozbrowseropenwindow event.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -23,9 +26,9 @@ function runTest() {
     is(popupFrame.getAttribute("name"), "OpenNamed");
 
     // Called when file_browserElement_OpenNamed2.html loads into popupFrame.
-    popupFrame.addEventListener("mozbrowsershowmodalprompt", function(e) {
+    popupFrame.addEventListener("mozbrowsershowmodalprompt", function(f) {
       ok(gotPopup, "Got openwindow event before showmodalprompt event.");
-      is(e.detail.message, "success: loaded");
+      is(f.detail.message, "success: loaded");
       SimpleTest.executeSoon(test2);
     }, {once: true});
 
diff --git a/dom/browser-element/mochitest/browserElement_OpenTab.js b/dom/browser-element/mochitest/browserElement_OpenTab.js
index d61d0bd44167..41a08efb68da 100644
--- a/dom/browser-element/mochitest/browserElement_OpenTab.js
+++ b/dom/browser-element/mochitest/browserElement_OpenTab.js
@@ -4,6 +4,9 @@
 // Bug 1144015 - test middle/ctrl/cmd-click on a link.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_OpenWindow.js b/dom/browser-element/mochitest/browserElement_OpenWindow.js
index 6ecfe7ca9ede..53e89ded2e3a 100644
--- a/dom/browser-element/mochitest/browserElement_OpenWindow.js
+++ b/dom/browser-element/mochitest/browserElement_OpenWindow.js
@@ -4,6 +4,9 @@
 // Bug 742944 - Test that window.open works with <iframe mozbrowser>.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_OpenWindowDifferentOrigin.js b/dom/browser-element/mochitest/browserElement_OpenWindowDifferentOrigin.js
index e38b42ca5639..bbcdb19dde28 100644
--- a/dom/browser-element/mochitest/browserElement_OpenWindowDifferentOrigin.js
+++ b/dom/browser-element/mochitest/browserElement_OpenWindowDifferentOrigin.js
@@ -4,6 +4,9 @@
 // Bug 769182 - window.open to a different origin should load the page.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -15,12 +18,12 @@ function runTest() {
   iframe.addEventListener("mozbrowseropenwindow", function(e) {
     ok(true, "Got first window.open call");
 
-    e.detail.frameElement.addEventListener("mozbrowseropenwindow", function(e) {
+    e.detail.frameElement.addEventListener("mozbrowseropenwindow", function(f) {
       ok(true, "Got second window.open call");
-      document.body.appendChild(e.detail.frameElement);
+      document.body.appendChild(f.detail.frameElement);
     });
 
-    e.detail.frameElement.addEventListener("mozbrowsershowmodalprompt", function(e) {
+    e.detail.frameElement.addEventListener("mozbrowsershowmodalprompt", function(f) {
       ok(true, "Got alert from second window.");
       SimpleTest.finish();
     });
diff --git a/dom/browser-element/mochitest/browserElement_OpenWindowEmpty.js b/dom/browser-element/mochitest/browserElement_OpenWindowEmpty.js
index 71b82d989390..8ec13011b50e 100644
--- a/dom/browser-element/mochitest/browserElement_OpenWindowEmpty.js
+++ b/dom/browser-element/mochitest/browserElement_OpenWindowEmpty.js
@@ -5,6 +5,9 @@
 // about:blank as default
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_OpenWindowInFrame.js b/dom/browser-element/mochitest/browserElement_OpenWindowInFrame.js
index 07eac2e33fc8..44a726880d4b 100644
--- a/dom/browser-element/mochitest/browserElement_OpenWindowInFrame.js
+++ b/dom/browser-element/mochitest/browserElement_OpenWindowInFrame.js
@@ -10,6 +10,9 @@
 // an iframe.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_OpenWindowRejected.js b/dom/browser-element/mochitest/browserElement_OpenWindowRejected.js
index c975937332c1..3b66f24dbe74 100644
--- a/dom/browser-element/mochitest/browserElement_OpenWindowRejected.js
+++ b/dom/browser-element/mochitest/browserElement_OpenWindowRejected.js
@@ -5,6 +5,9 @@
 // reject the call.  This shouldn't cause problems (crashes, leaks).
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_OpenWindowRejected2.js b/dom/browser-element/mochitest/browserElement_OpenWindowRejected2.js
index 1a8ca9fb3743..f260bf32fb99 100644
--- a/dom/browser-element/mochitest/browserElement_OpenWindowRejected2.js
+++ b/dom/browser-element/mochitest/browserElement_OpenWindowRejected2.js
@@ -9,6 +9,9 @@
 // preventDefault() on the event.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_Opensearch.js b/dom/browser-element/mochitest/browserElement_Opensearch.js
index a3d5c9889d83..7fa776f0631c 100644
--- a/dom/browser-element/mochitest/browserElement_Opensearch.js
+++ b/dom/browser-element/mochitest/browserElement_Opensearch.js
@@ -4,6 +4,8 @@
 // Test that the onmozbrowseropensearch event works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_PrivateBrowsing.js b/dom/browser-element/mochitest/browserElement_PrivateBrowsing.js
index a792e4bbccc6..365b7df8f109 100644
--- a/dom/browser-element/mochitest/browserElement_PrivateBrowsing.js
+++ b/dom/browser-element/mochitest/browserElement_PrivateBrowsing.js
@@ -4,6 +4,8 @@
 // Test that the mozprivatebrowsing attribute works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_PromptCheck.js b/dom/browser-element/mochitest/browserElement_PromptCheck.js
index 42fdc9d28bed..8f4454c6cef4 100644
--- a/dom/browser-element/mochitest/browserElement_PromptCheck.js
+++ b/dom/browser-element/mochitest/browserElement_PromptCheck.js
@@ -10,6 +10,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -37,6 +39,7 @@ function runTest() {
     }
   });
 
+  /* eslint-disable no-useless-concat */
   iframe.src =
     'data:text/html,<html><body><script>\
       addEventListener("load", function() { \
@@ -48,6 +51,7 @@ function runTest() {
        }); \
      }); \
      </scr' + "ipt></body></html>";
+   /* eslint-enable no-useless-concat */
 }
 
 // The test harness sets dom.successive_dialog_time_limit to 0 for some bizarre
diff --git a/dom/browser-element/mochitest/browserElement_PromptConfirm.js b/dom/browser-element/mochitest/browserElement_PromptConfirm.js
index 17967b250c37..238b2a39a493 100644
--- a/dom/browser-element/mochitest/browserElement_PromptConfirm.js
+++ b/dom/browser-element/mochitest/browserElement_PromptConfirm.js
@@ -8,6 +8,8 @@
 // ourselves.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -68,6 +70,7 @@ function runTest() {
     }
   });
 
+  /* eslint-disable no-useless-concat */
   iframe.src =
     'data:text/html,<html><body><script>\
       function sendVal(val) { \
@@ -81,6 +84,7 @@ function runTest() {
       sendVal(prompt("6", "initial")); \
       sendVal(prompt("7", "initial")); \
     </scr' + "ipt></body></html>";
+  /* eslint-enable no-useless-concat */
 }
 
 addEventListener("testready", runTest);
diff --git a/dom/browser-element/mochitest/browserElement_Reload.js b/dom/browser-element/mochitest/browserElement_Reload.js
index 575872561ffe..d86d77cf3723 100644
--- a/dom/browser-element/mochitest/browserElement_Reload.js
+++ b/dom/browser-element/mochitest/browserElement_Reload.js
@@ -4,6 +4,10 @@
 // Bug 741717 - Test the reload ability of <iframe mozbrowser>.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+/* eslint-env mozilla/frame-script */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_ReloadPostRequest.js b/dom/browser-element/mochitest/browserElement_ReloadPostRequest.js
index 8f8c72f30137..20ea422bd0f1 100644
--- a/dom/browser-element/mochitest/browserElement_ReloadPostRequest.js
+++ b/dom/browser-element/mochitest/browserElement_ReloadPostRequest.js
@@ -5,6 +5,9 @@
 // POST respest.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 SimpleTest.requestFlakyTimeout("untriaged");
 browserElementTestHelpers.setEnabledPref(true);
@@ -17,10 +20,8 @@ var isPostRequestSubmitted;
 
 function getExpectedStrings() {
   let result = {};
-  let bundleService = SpecialPowers.Cc["@mozilla.org/intl/stringbundle;1"].
-    getService(SpecialPowers.Ci.nsIStringBundleService);
-  let appBundle = bundleService.createBundle("chrome://global/locale/appstrings.properties");
-  let brandBundle = bundleService.createBundle("chrome://branding/locale/brand.properties");
+  let appBundle = Services.strings.createBundle("chrome://global/locale/appstrings.properties");
+  let brandBundle = Services.strings.createBundle("chrome://branding/locale/brand.properties");
   try {
     let brandName = brandBundle.GetStringFromName("brandShortName");
     result.message = appBundle.formatStringFromName("confirmRepostPrompt",
diff --git a/dom/browser-element/mochitest/browserElement_RemoveBrowserElement.js b/dom/browser-element/mochitest/browserElement_RemoveBrowserElement.js
index 30c04765b4f8..5fef7bd28ec8 100644
--- a/dom/browser-element/mochitest/browserElement_RemoveBrowserElement.js
+++ b/dom/browser-element/mochitest/browserElement_RemoveBrowserElement.js
@@ -6,6 +6,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_ScrollEvent.js b/dom/browser-element/mochitest/browserElement_ScrollEvent.js
index aba22759ad87..b7473de5ab1b 100644
--- a/dom/browser-element/mochitest/browserElement_ScrollEvent.js
+++ b/dom/browser-element/mochitest/browserElement_ScrollEvent.js
@@ -4,6 +4,8 @@
 // Test that scroll event bubbles up.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_SecurityChange.js b/dom/browser-element/mochitest/browserElement_SecurityChange.js
index 8ef0263a0181..6b5258dfa9a4 100644
--- a/dom/browser-element/mochitest/browserElement_SecurityChange.js
+++ b/dom/browser-element/mochitest/browserElement_SecurityChange.js
@@ -5,6 +5,9 @@
 // mozbrowsersecuritychange events.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -55,4 +58,3 @@ addEventListener("testready", function() {
     ["browser.safebrowsing.malware.enabled", false],
   ]}, runTest);
 });
-
diff --git a/dom/browser-element/mochitest/browserElement_SendEvent.js b/dom/browser-element/mochitest/browserElement_SendEvent.js
index abad7dc4723e..8ac715370d2d 100644
--- a/dom/browser-element/mochitest/browserElement_SendEvent.js
+++ b/dom/browser-element/mochitest/browserElement_SendEvent.js
@@ -4,6 +4,8 @@
 // Test that sendMouseEvent dispatch events.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 
diff --git a/dom/browser-element/mochitest/browserElement_Stop.js b/dom/browser-element/mochitest/browserElement_Stop.js
index d8261d4fb109..5c3681c7af06 100644
--- a/dom/browser-element/mochitest/browserElement_Stop.js
+++ b/dom/browser-element/mochitest/browserElement_Stop.js
@@ -9,6 +9,9 @@
 // image load will be cancaelled and mozbrowserloadend should be called.
 
 "use strict";
+
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 SimpleTest.requestFlakyTimeout("untriaged");
 browserElementTestHelpers.setEnabledPref(true);
diff --git a/dom/browser-element/mochitest/browserElement_TargetBlank.js b/dom/browser-element/mochitest/browserElement_TargetBlank.js
index 5ca4772cd190..f9e0eb3f56a3 100644
--- a/dom/browser-element/mochitest/browserElement_TargetBlank.js
+++ b/dom/browser-element/mochitest/browserElement_TargetBlank.js
@@ -5,6 +5,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_TargetTop.js b/dom/browser-element/mochitest/browserElement_TargetTop.js
index 0d7daa4e6e30..4f769f33f667 100644
--- a/dom/browser-element/mochitest/browserElement_TargetTop.js
+++ b/dom/browser-element/mochitest/browserElement_TargetTop.js
@@ -5,6 +5,8 @@
 // mozbrowser>.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_ThemeColor.js b/dom/browser-element/mochitest/browserElement_ThemeColor.js
index 7d8aa8546604..cb2fae050be0 100644
--- a/dom/browser-element/mochitest/browserElement_ThemeColor.js
+++ b/dom/browser-element/mochitest/browserElement_ThemeColor.js
@@ -4,6 +4,8 @@
 // Test that the onmozbrowsermetachange event for theme-color works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -82,4 +84,3 @@ function runTest() {
 }
 
 window.addEventListener("testready", runTest);
-
diff --git a/dom/browser-element/mochitest/browserElement_Titlechange.js b/dom/browser-element/mochitest/browserElement_Titlechange.js
index f6378ae55c21..2827ac6e27af 100644
--- a/dom/browser-element/mochitest/browserElement_Titlechange.js
+++ b/dom/browser-element/mochitest/browserElement_Titlechange.js
@@ -4,6 +4,8 @@
 // Test that the onmozbrowsertitlechange event works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_TopBarrier.js b/dom/browser-element/mochitest/browserElement_TopBarrier.js
index a2d164ba1777..a9894ccfffe6 100644
--- a/dom/browser-element/mochitest/browserElement_TopBarrier.js
+++ b/dom/browser-element/mochitest/browserElement_TopBarrier.js
@@ -4,6 +4,8 @@
 // Test that an <iframe mozbrowser> is a window.{top,parent,frameElement} barrier.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_Viewmode.js b/dom/browser-element/mochitest/browserElement_Viewmode.js
index f36f58fbaf0c..75b9b3effb98 100644
--- a/dom/browser-element/mochitest/browserElement_Viewmode.js
+++ b/dom/browser-element/mochitest/browserElement_Viewmode.js
@@ -4,6 +4,8 @@
 // Test that the onmozbrowsermetachange event for viewmode works.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -68,4 +70,3 @@ function runTest() {
 }
 
 window.addEventListener("testready", runTest);
-
diff --git a/dom/browser-element/mochitest/browserElement_XFrameOptions.js b/dom/browser-element/mochitest/browserElement_XFrameOptions.js
index cdbdd14d76e1..a1a85700297c 100644
--- a/dom/browser-element/mochitest/browserElement_XFrameOptions.js
+++ b/dom/browser-element/mochitest/browserElement_XFrameOptions.js
@@ -5,6 +5,8 @@
 // <iframe mozbrowser>.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_XFrameOptionsAllowFrom.js b/dom/browser-element/mochitest/browserElement_XFrameOptionsAllowFrom.js
index 7c2bc279dac9..b50ca81e70bc 100644
--- a/dom/browser-element/mochitest/browserElement_XFrameOptionsAllowFrom.js
+++ b/dom/browser-element/mochitest/browserElement_XFrameOptionsAllowFrom.js
@@ -4,6 +4,8 @@
 // Bug 690168 - Support Allow-From notation for X-Frame-Options header.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
@@ -27,8 +29,6 @@ function arrayBuffersEqual(a, b) {
 }
 
 function runTest() {
-  var count = 0;
-
   var iframe = document.createElement("iframe");
   iframe.setAttribute("mozbrowser", "true");
   iframe.height = "1000px";
diff --git a/dom/browser-element/mochitest/browserElement_XFrameOptionsDeny.js b/dom/browser-element/mochitest/browserElement_XFrameOptionsDeny.js
index 1937f9c67f52..26f5254445a4 100644
--- a/dom/browser-element/mochitest/browserElement_XFrameOptionsDeny.js
+++ b/dom/browser-element/mochitest/browserElement_XFrameOptionsDeny.js
@@ -5,6 +5,8 @@
 // subframe of <iframe mozbrowser>.
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/browserElement_XFrameOptionsSameOrigin.js b/dom/browser-element/mochitest/browserElement_XFrameOptionsSameOrigin.js
index 815f4a644770..36074a4838c1 100644
--- a/dom/browser-element/mochitest/browserElement_XFrameOptionsSameOrigin.js
+++ b/dom/browser-element/mochitest/browserElement_XFrameOptionsSameOrigin.js
@@ -7,6 +7,8 @@
 
 "use strict";
 
+/* global browserElementTestHelpers */
+
 SimpleTest.waitForExplicitFinish();
 browserElementTestHelpers.setEnabledPref(true);
 browserElementTestHelpers.addPermission();
diff --git a/dom/browser-element/mochitest/file_browserElement_FrameWrongURI.html b/dom/browser-element/mochitest/file_browserElement_FrameWrongURI.html
index 1a6cfde0a566..a1db6eb6f5f8 100644
--- a/dom/browser-element/mochitest/file_browserElement_FrameWrongURI.html
+++ b/dom/browser-element/mochitest/file_browserElement_FrameWrongURI.html
@@ -1,5 +1,6 @@
 <script>
   function testSucceeded() { alert("success"); }
+  // eslint-disable-next-line no-useless-concat
   function callback() { return "<script>opener.testSucceeded()</" + "script>"; }
   var w = window.open("javascript:opener.callback();");
 </script>
diff --git a/dom/browser-element/mochitest/file_browserElement_LoadEvents.html b/dom/browser-element/mochitest/file_browserElement_LoadEvents.html
index a9dcb990e2d1..a2bf2d3e1080 100644
--- a/dom/browser-element/mochitest/file_browserElement_LoadEvents.html
+++ b/dom/browser-element/mochitest/file_browserElement_LoadEvents.html
@@ -7,6 +7,7 @@
 Aloha!  My URL is <span id='url'></span>.
 
 <script>
+// eslint-disable-next-line no-unsanitized/property
 document.getElementById("url").innerHTML = window.location;
 </script>
 
diff --git a/dom/browser-element/mochitest/file_browserElement_OpenWindowDifferentOrigin.html b/dom/browser-element/mochitest/file_browserElement_OpenWindowDifferentOrigin.html
index 67a25fb6ef8b..9dbf2efecd32 100644
--- a/dom/browser-element/mochitest/file_browserElement_OpenWindowDifferentOrigin.html
+++ b/dom/browser-element/mochitest/file_browserElement_OpenWindowDifferentOrigin.html
@@ -10,6 +10,7 @@ if (location.search == "?1") {
   alert("finish");
 }
 
+// eslint-disable-next-line no-unsanitized/property
 document.getElementById("name").innerHTML = location.search;
 </script>
 
diff --git a/dom/browser-element/mochitest/file_browserElement_TargetTop.html b/dom/browser-element/mochitest/file_browserElement_TargetTop.html
index a2602849af68..7eef973428e8 100644
--- a/dom/browser-element/mochitest/file_browserElement_TargetTop.html
+++ b/dom/browser-element/mochitest/file_browserElement_TargetTop.html
@@ -6,6 +6,7 @@
 if (location.search == "") {
   window.open("file_browserElement_TargetTop.html?2", "_top");
 }
+// eslint-disable-next-line no-unsanitized/property
 document.getElementById("url").innerHTML = document.location.href;
 </script>
 </body>
diff --git a/dom/browser-element/mochitest/file_browserElement_XFrameOptionsAllowFrom.html b/dom/browser-element/mochitest/file_browserElement_XFrameOptionsAllowFrom.html
index 4ee854c790b2..31920670d78c 100644
--- a/dom/browser-element/mochitest/file_browserElement_XFrameOptionsAllowFrom.html
+++ b/dom/browser-element/mochitest/file_browserElement_XFrameOptionsAllowFrom.html
@@ -23,9 +23,7 @@ document.body.appendChild(iframe1);
 iframe1.addEventListener("load", function() {
   // This causes our embedder to take a screenshot (and blocks until the
   // screenshot is completed).
-  var iframe2Loaded = false;
   iframe2.addEventListener("load", function() {
-    iframe2Loaded = true;
     alert("finish");
   }, {once: true});
 
diff --git a/dom/browser-element/mochitest/file_empty.html b/dom/browser-element/mochitest/file_empty.html
index fe819a9a765f..b3a7ddd27c2b 100644
--- a/dom/browser-element/mochitest/file_empty.html
+++ b/dom/browser-element/mochitest/file_empty.html
@@ -7,6 +7,7 @@
 Aloha!  My URL is <span id='url'></span>.
 
 <script>
+// eslint-disable-next-line no-unsanitized/property
 document.getElementById("url").innerHTML = window.location;
 </script>
 
diff --git a/dom/browser-element/mochitest/file_focus.html b/dom/browser-element/mochitest/file_focus.html
index 0eabb86bf512..139904633002 100644
--- a/dom/browser-element/mochitest/file_focus.html
+++ b/dom/browser-element/mochitest/file_focus.html
@@ -3,6 +3,7 @@
 
 Aloha!  My URL is <span id='url'></span>.
 <script>
+// eslint-disable-next-line no-unsanitized/property
 document.getElementById("url").innerHTML = window.location;
 </script>
 
@@ -13,8 +14,7 @@ document.getElementById("url").innerHTML = window.location;
   var alreadyBlocked = false;
 
   addEventListener("keydown", function(e) {
-    if (e.keyCode == KeyboardEvent.DOM_VK_ESCAPE &&
-        alreadyBlocked == false) {
+    if (e.keyCode == KeyboardEvent.DOM_VK_ESCAPE && !alreadyBlocked) {
       alreadyBlocked = true;
       e.preventDefault();
     }
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js
index e951d62bc47e..2275030a110b 100644
--- a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js
@@ -10,6 +10,7 @@ module.exports = {
   "globals": {
     // SpecialPowers is injected into the window object via SimpleTest.js
     "SpecialPowers": false,
+    "XPCNativeWrapper": false,
   },
 
   "overrides": [{