WebUI: Enable ESLint rule for missing semicolons.

chrome/browser/resources/chromeos/login/oobe_welcome.js

 // Copyright 2016 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.
 
 /**
  * @fileoverview Polymer element for displaying material design OOBE.
  */
 
 Polymer({
   is: 'oobe-welcome-md',
@@ skipping 121 matching lines @@
     };
   },
 
   /**
    * Hides all screens to help switching from one screen to another.
    * @private
    */
   hideAllScreens_: function() {
     this.$.welcomeScreen.hidden = true;
 
-    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog')
+    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog');
     for (var i = 0; i < screens.length; ++i) {
       screens[i].hidden = true;
     }
   },
 
   /**
    * Shows given screen.
    * @param id String Screen ID.
    * @private
    */
   showScreen_: function(id) {
     this.hideAllScreens_();
 
     var screen = this.$[id];
     assert(screen);
     screen.hidden = false;
     screen.show();
   },
 
   /**
    * Returns active screen object.
    * @private
    */
   getActiveScreen_: function() {
-    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog')
+    var screens = Polymer.dom(this.root).querySelectorAll('oobe-dialog');
     for (var i = 0; i < screens.length; ++i) {
       if (!screens[i].hidden)
         return screens[i];
     }
     return this.$.welcomeScreen;
   },
 
   focus: function() {
     this.getActiveScreen_().focus();
   },
@@ skipping 309 matching lines @@
    * @private
    */
   onTimezoneSelected_: function(event) {
     var item = event.detail;
     if (!item)
       return;
 
     this.screen.onTimezoneSelected_(item.value);
   },
 });