Handle authentication failures in the v2 app by restarting the app

remoting/webapp/crd/js/it2me_helpee_channel.js

 // Copyright 2014 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
  *
  * It2MeHelpeeChannel relays messages between the Hangouts web page (Hangouts)
  * and the It2Me Native Messaging Host (It2MeHost) for the helpee (the Hangouts
  * participant who is receiving remoting assistance).
@@ skipping 384 matching lines @@
       var onAuthenticated = function() {
         oauth2.callWithToken(
             resolve,
             function() { throw new Error('Authentication failed.'); });
       };
       /** @param {remoting.Error} error */
       var onError = function(error) {
         if (error != remoting.Error.NOT_AUTHENTICATED) {
           throw new Error('Unexpected error fetch auth token: ' + error);
         }
-        oauth2.doAuthRedirect(onAuthenticated);
+        oauth2.removeCachedAuthToken(base.doNothing);
       };
       oauth2.callWithToken(resolve, onError);
     });
   }
 };
 
 /**
  * Connects to the It2Me Native Messaging Host and retrieves the access code
  * in the |onHostStateChanged_| callback.
  *
@@ skipping 72 matching lines @@
 
   console.error('Error responding to message method:' +
                 (incomingMessage ? incomingMessage.method : 'null') +
                 ' error:' + error);
   this.hangoutPort_.postMessage({
     method: remoting.It2MeHelpeeChannel.HangoutMessageTypes.ERROR,
     message: error,
     request: incomingMessage
   });
 };