Show a helpful error message if a host domain policy blocked an attempt to use

remoting/webapp/host_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 'host screen' for Chromoting.
  */
 
 'use strict';
@@ skipping 103 matching lines @@
         remoting.setMode(remoting.AppMode.HOME);
       } else {
         remoting.setMode(remoting.AppMode.HOST_SHARE_FINISHED);
       }
     }
     remoting.hostSession.removePlugin();
 
   } else if (state == remoting.HostSession.State.ERROR) {
     console.error('Host plugin state: ERROR');
     showShareError_(remoting.Error.UNEXPECTED);
+  } else if (state == remoting.HostSession.State.INVALID_DOMAIN_ERROR) {
+    console.error('Host plugin state: INVALID_DOMAIN_ERROR');
+    showShareError_(remoting.Error.INVALID_HOST_DOMAIN);
   } else {
     console.error('Unknown state -> ' + state);
   }
 }
 
 /**
  * This is the callback that the host plugin invokes to indicate that there
  * is additional debug log info to display.
  * @param {string} msg The message (which will not be localized) to be logged.
  */
@@ skipping 130 matching lines @@
  * @return {void} Nothing.
  */
 function onNatTraversalPolicyChanged_(enabled) {
   var natBox = document.getElementById('nat-box');
   if (enabled) {
     natBox.classList.add('traversal-enabled');
   } else {
     natBox.classList.remove('traversal-enabled');
   }
 }