Fixed callWithToken error handling.

remoting/webapp/client_screen.js

 // Copyright (c) 2012 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
  * Functions related to the 'client screen' for Chromoting.
  */
 
 'use strict';
@@ skipping 296 matching lines @@
   console.log('Starting session...');
   var accessCode = document.getElementById('access-code-entry');
   accessCode.value = '';  // The code has been validated and won't work again.
   remoting.clientSession =
       new remoting.ClientSession(
           remoting.hostJid, remoting.hostPublicKey,
           remoting.accessCode, 'v1_token', '',
           /** @type {string} */ (remoting.oauth2.getCachedEmail()),
           remoting.ClientSession.Mode.IT2ME,
           onClientStateChange_);
-  /** @param {string} token The auth token. */
+  /** @param {string?} token The auth token. */
   var createPluginAndConnect = function(token) {
-    remoting.clientSession.createPluginAndConnect(
-        document.getElementById('session-mode'),
-        token);
+    if (token) {
+      remoting.clientSession.createPluginAndConnect(
+          document.getElementById('session-mode'),
+          token);
+    } else {
+      showConnectError_(remoting.Error.AUTHENTICATION_FAILED);
+    }
   };
   remoting.oauth2.callWithToken(createPluginAndConnect);
 }
 
 /**
  * Show a client-side error message.
  *
  * @param {remoting.Error} errorTag The error to be localized and
  *     displayed.
  * @return {void} Nothing.
@@ skipping 192 matching lines @@
             pin, 'spake2_hmac,spake2_plain', remoting.hostId,
             /** @type {string} */ (remoting.oauth2.getCachedEmail()),
             remoting.ClientSession.Mode.ME2ME, onClientStateChange_);
     remoting.clientSession.createPluginAndConnect(
         document.getElementById('session-mode'),
         token);
   } else {
     showConnectError_(remoting.Error.AUTHENTICATION_FAILED);
   }
 }