Browser Plugin: Implement AutoSize

content/test/data/browser_plugin_embedder.html

 <script type="text/javascript">
 function loadAbort(evt) {
   document.title = evt.type;
 }
 function loadStart(evt) {
   document.title = evt.url;
 }
 function loadStop(evt) {
   document.title = "loadStop";
 }
@@ skipping 83 matching lines @@
     }
   }
 }
   var plugin = document.getElementById('plugin');
   plugin.addEventListener('loadstart', loadStart);
   plugin.addEventListener('loadabort', loadAbort);
   plugin.addEventListener('loadredirect', loadRedirect);
   window.addEventListener('message', receiveMessage, false);
   plugin.addEventListener('loadstop', loadStop);
   plugin.addEventListener('loadcommit', loadCommit);
+  plugin.addEventListener('sizechanged', sizeChanged);
 </script>