[ChromeOS] Use oauth's segmented spinner for sign-in loading UI.

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

 // Copyright (c) 2011 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 Oobe signin screen implementation.
  */
 
 cr.define('login', function() {
   /**
@@ skipping 45 matching lines @@
       signinButton.id = 'signin-button';
       signinButton.textContent = localStrings.getString('signinButton');
       signinButton.addEventListener('click',
           this.handleSigninClick_.bind(this));
       buttons.push(signinButton);
 
       return buttons;
     },
 
     /**
-     * Helper function to toggle throbber and input fields.
+     * Helper function to toggle spinner and input fields.
      * @param {boolean} enable True to enable credential input UI.
      * @private
      */
     enableInputs_: function(enable) {
-      $('login-throbber').hidden = enable;
+      $('login-spinner').hidden = enable;
       $('email').hidden = !enable;
       $('password').hidden = !enable;
       $('signin-button').hidden = !enable;
     },
 
     /**
      * Sets UI state.
      */
     set state(newState) {
       if (newState == SigninScreen.STATE_INPUT) {
@@ skipping 72 matching lines @@
       var emailElement = $('email');
       if (emailElement.value && emailElement.value.indexOf('@') == -1)
         emailElement.value += '@gmail.com';
     }
   };
 
   return {
     SigninScreen: SigninScreen
   };
 });