--- a/browser/.eslintrc.js
+++ b/browser/.eslintrc.js
@@ -2,11 +2,11 @@
 
 module.exports = {
   "extends": [
     "../toolkit/.eslintrc.js"
   ],
 
   "rules": {
     "no-shadow": "error",
-    "no-undef": "off"
+    "no-undef": "error"
   }
 };

--- a/browser/base/.eslintrc.js
+++ b/browser/base/.eslintrc.js
@@ -1,4 +1,7 @@
 "use strict";
 
 module.exports = {
+  rules: {
+    "no-undef": "off"
+  }
 };

new file mode 100644
--- /dev/null
+++ b/browser/components/.eslintrc.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+  rules: {
+    "no-undef": "off"
+  }
+};

--- a/browser/extensions/pocket/content/main.js
+++ b/browser/extensions/pocket/content/main.js
@@ -37,16 +37,17 @@
 
 // TODO : Get the toolbar icons from Firefox's build (Nikki needs to give us a red saved icon)
 // TODO : [needs clarificaiton from Fx] Firefox's plan was to hide Pocket from context menus until the user logs in. Now that it's an extension I'm wondering if we still need to do this.
 // TODO : [needs clarificaiton from Fx] Reader mode (might be a something they need to do since it's in html, need to investigate their code)
 // TODO : [needs clarificaiton from Fx] Move prefs within pktApi.s to sqlite or a local file so it's not editable (and is safer)
 // TODO : [nice to have] - Immediately save, buffer the actions in a local queue and send (so it works offline, works like our native extensions)
 
 /* eslint-disable no-shadow */
+/* eslint "mozilla/import-browserjs-globals": "error" */
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
   "resource://gre/modules/PrivateBrowsingUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "ReaderMode",
   "resource://gre/modules/ReaderMode.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "pktApi",
   "chrome://pocket/content/pktApi.jsm");

--- a/browser/extensions/presentation/bootstrap.js
+++ b/browser/extensions/presentation/bootstrap.js
@@ -53,32 +53,34 @@ Factory.prototype = {
   },
 };
 
 var Presentation = {
   // PUBLIC APIs
   init() {
     log("init");
     // Register PresentationDevicePrompt into a XPCOM component.
-    Cu.import(PRESENTATION_DEVICE_PROMPT_PATH);
+    let {PresentationDevicePrompt} = Cu.import(PRESENTATION_DEVICE_PROMPT_PATH, {});
+    this.PresentationDevicePrompt = PresentationDevicePrompt;
     this._register();
   },
 
   uninit() {
     log("uninit");
     // Unregister PresentationDevicePrompt XPCOM component.
     this._unregister();
+    delete this.PresentationDevicePrompt;
     Cu.unload(PRESENTATION_DEVICE_PROMPT_PATH);
   },
 
   // PRIVATE APIs
   _register() {
     log("_register");
     this._devicePromptFactory = new Factory();
-    this._devicePromptFactory.register(PresentationDevicePrompt);
+    this._devicePromptFactory.register(this.PresentationDevicePrompt);
   },
 
   _unregister() {
     log("_unregister");
     this._devicePromptFactory.unregister();
     delete this._devicePromptFactory;
   },
 };

--- a/browser/extensions/shield-recipe-client/lib/CleanupManager.jsm
+++ b/browser/extensions/shield-recipe-client/lib/CleanupManager.jsm
@@ -1,14 +1,16 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
+const {utils: Cu} = Components;
+
 this.EXPORTED_SYMBOLS = ["CleanupManager"];
 
 const cleanupHandlers = new Set();
 
 this.CleanupManager = {
   addCleanupHandler(handler) {
     cleanupHandlers.add(handler);
   },

--- a/browser/extensions/webcompat-reporter/bootstrap.js
+++ b/browser/extensions/webcompat-reporter/bootstrap.js
@@ -1,12 +1,14 @@
 /* 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/. */
 
+/* global APP_SHUTDOWN:false */
+
 let { classes: Cc, interfaces: Ci, utils: Cu } = Components;
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const WEBCOMPATREPORTER_JSM = "chrome://webcompat-reporter/content/WebCompatReporter.jsm";
 
 XPCOMUtils.defineLazyModuleGetter(this, "WebCompatReporter",

--- a/browser/extensions/webcompat-reporter/content/WebCompatReporter.jsm
+++ b/browser/extensions/webcompat-reporter/content/WebCompatReporter.jsm
@@ -26,16 +26,17 @@ const TABLISTENER_JSM = "chrome://webcom
 
 let WebCompatReporter = {
   get endpoint() {
     return Services.urlFormatter.formatURLPref(
       "extensions.webcompat-reporter.newIssueEndpoint");
   },
 
   init() {
+    /* global TabListener */
     Cu.import(TABLISTENER_JSM);
 
     let styleSheetService = Cc["@mozilla.org/content/style-sheet-service;1"]
       .getService(Ci.nsIStyleSheetService);
     this._sheetType = styleSheetService.AUTHOR_SHEET;
     this._cachedSheet = styleSheetService.preloadSheet(wcStyleURI,
                                                        this._sheetType);
 

--- a/browser/extensions/webcompat-reporter/content/tab-frame.js
+++ b/browser/extensions/webcompat-reporter/content/tab-frame.js
@@ -1,12 +1,14 @@
 /* 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/. */
 
+/* global content:false, sendAsyncMessage:false */
+
 let { utils: Cu } = Components;
 
 const TABDATA_MESSAGE = "WebCompat:SendTabData";
 
 let getScreenshot = function(win) {
   return new Promise(resolve => {
     let url = win.location.href;
     try {

--- a/browser/extensions/webcompat-reporter/content/wc-frame.js
+++ b/browser/extensions/webcompat-reporter/content/wc-frame.js
@@ -1,12 +1,14 @@
 /* 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/. */
 
+/* global content:false, addMessageListener:false, removeMessageListener: false */
+
 let { utils: Cu } = Components;
 
 const SCREENSHOT_MESSAGE = "WebCompat:SendScreenshot";
 
 addMessageListener(SCREENSHOT_MESSAGE, function handleMessage(message) {
   removeMessageListener(SCREENSHOT_MESSAGE, handleMessage);
   // postMessage the screenshot blob from a content Sandbox so message event.origin
   // is what we expect on the client-side (i.e., https://webcompat.com)

new file mode 100644
--- /dev/null
+++ b/browser/extensions/webcompat/test/.eslintrc.js
@@ -0,0 +1,7 @@
+"use strict";
+
+module.exports = {
+  "extends": [
+    "../../../../testing/mochitest/browser.eslintrc.js"
+  ]
+};

--- a/browser/modules/test/browser_NetworkPrioritizer.js
+++ b/browser/modules/test/browser_NetworkPrioritizer.js
@@ -14,34 +14,36 @@ const DELTA = NORMAL - LOW; // lower val
 
 // Test helper functions.
 // getPriority and setPriority can take a tab or a Browser
 function* getPriority(aBrowser) {
   if (aBrowser.localName == "tab")
     aBrowser = aBrowser.linkedBrowser;
 
   return yield ContentTask.spawn(aBrowser, null, function* () {
-    return docShell.QueryInterface(Components.interfaces.nsIWebNavigation)
-                   .QueryInterface(Components.interfaces.nsIDocumentLoader)
-                   .loadGroup
-                   .QueryInterface(Components.interfaces.nsISupportsPriority)
-                   .priority;
+    return content.document.docShell
+      .QueryInterface(Components.interfaces.nsIWebNavigation)
+      .QueryInterface(Components.interfaces.nsIDocumentLoader)
+      .loadGroup
+      .QueryInterface(Components.interfaces.nsISupportsPriority)
+      .priority;
   });
 }
 
 function* setPriority(aBrowser, aPriority) {
   if (aBrowser.localName == "tab")
     aBrowser = aBrowser.linkedBrowser;
 
   yield ContentTask.spawn(aBrowser, aPriority, function* (contentPriority) {
-    docShell.QueryInterface(Components.interfaces.nsIWebNavigation)
-                                    .QueryInterface(Components.interfaces.nsIDocumentLoader)
-                                    .loadGroup
-                                    .QueryInterface(Ci.nsISupportsPriority)
-                                    .priority = contentPriority;
+    content.document.docShell
+      .QueryInterface(Components.interfaces.nsIWebNavigation)
+      .QueryInterface(Components.interfaces.nsIDocumentLoader)
+      .loadGroup
+      .QueryInterface(Ci.nsISupportsPriority)
+      .priority = contentPriority;
   });
 }
 
 function* isWindowState(aWindow, aTabPriorities) {
   let browsers = aWindow.gBrowser.browsers;
   // Make sure we have the right number of tabs & priorities
   is(browsers.length, aTabPriorities.length,
      "Window has expected number of tabs");

--- a/browser/modules/test/contentSearch.js
+++ b/browser/modules/test/contentSearch.js
@@ -1,12 +1,14 @@
 /* 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/. */
 
+/* global addMessageListener:false, sendAsyncMessage:false, XPCOMUtils */
+
 const TEST_MSG = "ContentSearchTest";
 const SERVICE_EVENT_TYPE = "ContentSearchService";
 const CLIENT_EVENT_TYPE = "ContentSearchClient";
 
 // Forward events from the in-content service to the test.
 content.addEventListener(SERVICE_EVENT_TYPE, event => {
   // The event dispatch code in content.js clones the event detail into the
   // content scope. That's generally the right thing, but causes us to end
@@ -33,18 +35,18 @@ addMessageListener(TEST_MSG, msg => {
     new content.CustomEvent(CLIENT_EVENT_TYPE, {
       detail: msg.data,
     })
   );
 });
 
 function waitForLoadAndStopIt(expectedURL, callback) {
   let Ci = Components.interfaces;
-  let webProgress = docShell.QueryInterface(Ci.nsIInterfaceRequestor)
-                            .getInterface(Ci.nsIWebProgress);
+  let webProgress = content.document.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
+                                             .getInterface(Ci.nsIWebProgress);
   let listener = {
     onStateChange(webProg, req, flags, status) {
       if (req instanceof Ci.nsIChannel) {
         let url = req.originalURI.spec;
         dump("waitForLoadAndStopIt: onStateChange " + url + "\n");
         let docStart = Ci.nsIWebProgressListener.STATE_IS_DOCUMENT |
                        Ci.nsIWebProgressListener.STATE_START;
         if ((flags & docStart) && webProg.isTopLevel && url == expectedURL) {

--- a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browserjs-globals.js
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browserjs-globals.js
@@ -49,23 +49,26 @@ const SCRIPTS = [
   "browser/base/content/browser-trackingprotection.js",
   "browser/base/content/browser-data-submission-info-bar.js",
   "browser/base/content/browser-fxaccounts.js"
 ];
 
 module.exports = function(context) {
   return {
     Program: function(node) {
-      if (helpers.getTestType(this) != "browser" &&
-          !helpers.getIsHeadFile(this)) {
+      let filepath = helpers.getAbsoluteFilePath(context);
+      let root = helpers.getRootDir(filepath);
+      let relativepath = path.relative(root, filepath);
+
+      if ((helpers.getTestType(this) != "browser" &&
+          !helpers.getIsHeadFile(this)) &&
+          !relativepath.includes("content")) {
         return;
       }
 
-      let filepath = helpers.getAbsoluteFilePath(context);
-      let root = helpers.getRootDir(filepath);
       for (let script of SCRIPTS) {
         let fileName = path.join(root, script);
         try {
           let newGlobals = globals.getGlobalsForFile(fileName);
           helpers.addGlobals(newGlobals, context.getScope());
         } catch (e) {
           context.report(
             node,

--- a/tools/lint/eslint/eslint-plugin-mozilla/package.json
+++ b/tools/lint/eslint/eslint-plugin-mozilla/package.json
@@ -1,11 +1,11 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "0.2.17",
+  "version": "0.2.18",
   "description": "A collection of rules that help enforce JavaScript coding standard in the Mozilla project.",
   "keywords": [
     "eslint",
     "eslintplugin",
     "eslint-plugin",
     "mozilla",
     "firefox"
   ],