<webview>: Make contentWindow available prior to attachment (on display:none).

chrome/test/data/extensions/platform_apps/web_view/shim/inject_comm_channel.js

 // Copyright 2013 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.
 
 var embedder = null;
 
 function reportConnected() {
+  window.console.log('Reporting connection to embedder.');
   var msg = ['connected'];
   embedder.postMessage(JSON.stringify(msg), '*');
 }
 
 window.addEventListener('message', function(e) {
   embedder = e.source;
   var data = JSON.parse(e.data);
   switch (data[0]) {
     case 'connect': {
       reportConnected();
       break;
     }
   }
 });
 
+
+window.console.log('Script has been successfully injected.');