Fix JSCompile.

remoting/webapp/background/background.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.
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 (function(){
 
 /** @param {remoting.AppLauncher} appLauncher */
@@ skipping 43 matching lines @@
   });
 
   remoting.settings = new remoting.Settings();
 
   chrome.runtime.onSuspendCanceled.addListener(initializeIt2MeService);
   initializeIt2MeService();
 }
 
 function main() {
   if (base.isAppsV2()) {
-    appLauncher = new remoting.V2AppLauncher();
+    var appLauncher = new remoting.V2AppLauncher();
     initializeAppV2(appLauncher);
   }
 }
 
 remoting.enableHangoutsRemoteAssistance = function() {
   /** @type {remoting.AppLauncher} */
   var appLauncher = base.isAppsV2() ? new remoting.V1AppLauncher():
                                       new remoting.V2AppLauncher();
   initializeBackgroundService(appLauncher);
 };
 
 window.addEventListener('load', main, false);
 
 }());