Update the code that gets an OAuth2 access token.

remoting/webapp/me2mom/oauth2.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
  * OAuth2 class that handles retrieval/storage of an OAuth2 token.
  *
  * Uses a content script to trampoline the OAuth redirect page back into the
  * extension context.  This works around the lack of native support for
@@ skipping 218 matching lines @@
  * Redirect page to get a new OAuth2 Refresh Token.
  *
  * @return {void} Nothing.
  */
 remoting.OAuth2.prototype.doAuthRedirect = function() {
   var GET_CODE_URL = 'https://accounts.google.com/o/oauth2/auth?' +
     remoting.xhr.urlencodeParamHash({
           'client_id': this.CLIENT_ID_,
           'redirect_uri': this.REDIRECT_URI_,
           'scope': this.SCOPE_,
-          'response_type': 'code'
+          'response_type': 'code',
+          'access_type': 'offline',
+          'approval_prompt': 'force'
         });
   window.location.replace(GET_CODE_URL);
 };
 
 /**
  * Asynchronously exchanges an authorization code for a refresh token.
  *
  * @param {string} code The new refresh token.
  * @param {function(XMLHttpRequest):void} onDone Callback to invoke on
  *     completion.
@@ skipping 87 matching lines @@
  * @return {?string} The email address, if it has been cached by a previous call
  *     to getEmail, otherwise null.
  */
 remoting.OAuth2.prototype.getCachedEmail = function() {
   var value = window.localStorage.getItem(this.KEY_EMAIL_);
   if (typeof value == 'string') {
     return value;
   }
   return null;
 };