Remove 'Enable' button on unsupported platforms. Added 'No hosts' message.

remoting/webapp/remoting.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.
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /** @type {remoting.HostSession} */ remoting.hostSession = null;
@@ skipping 21 matching lines @@
 remoting.init = function() {
   remoting.logExtensionInfoAsync_();
   l10n.localize();
   // Create global objects.
   remoting.oauth2 = new remoting.OAuth2();
   remoting.stats = new remoting.ConnectionStats(
       document.getElementById('statistics'));
   remoting.formatIq = new remoting.FormatIq();
   remoting.hostList = new remoting.HostList(
       document.getElementById('host-list'),
+      document.getElementById('host-list-empty'),
       document.getElementById('host-list-error-message'),
       document.getElementById('host-list-refresh-failed-button'));
   remoting.toolbar = new remoting.Toolbar(
       document.getElementById('session-toolbar'));
   remoting.clipboard = new remoting.Clipboard();
 
   refreshEmail_();
   var email = remoting.oauth2.getCachedEmail();
   if (email) {
     document.getElementById('current-email').innerText = email;
@@ skipping 281 matching lines @@
  */
 remoting.defaultOAuthErrorHandler = function(error) {
   l10n.localizeElementFromTag(
       document.getElementById('token-refresh-error-message'),
       error);
   var auth_failed = (error == remoting.Error.AUTHENTICATION_FAILED);
   document.getElementById('token-refresh-auth-failed').hidden = !auth_failed;
   document.getElementById('token-refresh-other-error').hidden = auth_failed;
   remoting.setMode(remoting.AppMode.TOKEN_REFRESH_FAILED);
 };