Typecheck some of ui/webui/resources/js/ with Closure compiler.

chrome/browser/resources/extensions/extension_error_overlay.js

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('extensions', function() {
   'use strict';
 
   /**
    * Clear all the content of a given element.
    * @param {HTMLElement} element The element to be cleared.
@@ skipping 59 matching lines @@
    * @see chrome/browser/ui/webui/extensions/extension_error_ui_util.h
    * @param {Object} args The arguments to pass to openDevTools.
    * @private
    */
   RuntimeErrorContent.openDevtools_ = function(args) {
     if (chrome.send)
       chrome.send('extensionErrorOpenDevTools', [args]);
     else if (chrome.developerPrivate)
       chrome.developerPrivate.openDevTools(args);
     else
-      assert(false, 'Cannot call either openDevTools function.');
+      assertNotReached('Cannot call either openDevTools function.');
   };
 
   RuntimeErrorContent.prototype = {
     __proto__: HTMLDivElement.prototype,
 
     /**
      * The underlying error whose details are being displayed.
      * @type {Object}
      * @private
      */
@@ skipping 237 matching lines @@
    * @param {Object} args The arguments to pass to requestFileSource.
    */
   ExtensionErrorOverlay.requestFileSource = function(args) {
     if (chrome.send) {
       chrome.send('extensionErrorRequestFileSource', [args]);
     } else if (chrome.developerPrivate) {
       chrome.developerPrivate.requestFileSource(args, function(result) {
         extensions.ExtensionErrorOverlay.requestFileSourceResponse(result);
       });
     } else {
-      assert(false, 'Cannot call either requestFileSource function.');
+      assertNotReached('Cannot call either requestFileSource function.');
     }
   };
 
   cr.addSingletonGetter(ExtensionErrorOverlay);
 
   ExtensionErrorOverlay.prototype = {
     /**
      * The underlying error whose details are being displayed.
      * @type {Object}
      * @private
@@ skipping 156 matching lines @@
     var overlay = extensions.ExtensionErrorOverlay.getInstance();
     overlay.setCode(result);
     overlay.setVisible(true);
   };
 
   // Export
   return {
     ExtensionErrorOverlay: ExtensionErrorOverlay
   };
 });