Browser Plugin: Add HTML5-like postMessage support

content/test/data/browser_plugin_embedder.html

Index: content/test/data/browser_plugin_embedder.html
diff --git a/content/test/data/browser_plugin_embedder.html b/content/test/data/browser_plugin_embedder.html
index 31a78467a65d57d70e50da1e131de0351542d808..b34f884d0e86c9e2d4fb2d410ec4f265e5443794 100644
--- a/content/test/data/browser_plugin_embedder.html
+++ b/content/test/data/browser_plugin_embedder.html
@@ -8,6 +8,10 @@ function SetSize(w, h) {
   plugin.width = w;
   plugin.height = h;
 }
+function PostMessage(data) {
+  plugin = document.getElementById('plugin');
+  plugin.postMessage('testing123', '');

[nasko, 2012/09/19 21:19:59]

The second param is the target origin, right? If yes, shouldn't it be '*'? In
general, should we be performing origin checks for delivering postMessage? It
will be nice to have some defensive mechanisms to prevent messages from reaching
unintended recipients. 

+}
 </script>
 
 <object id="plugin"
@@ -16,3 +20,15 @@ function SetSize(w, h) {
     width="640"
     height="480"
     border="0px"></object>
+<script type="text/javascript">
+var msg;
+function receiveMessage(event) {
+  msg = event.data;
+  if (msg != 'stop_ack') {

[nasko, 2012/09/19 21:19:59]

Shouldn't that be !==?

[Fady Samuel, 2012/09/20 15:24:28]

Done.

+    event.source.postMessage('stop', '*');
+  } else {
+    window.document.title = 'stop_ack';
+  }
+}
+document.getElementById('plugin').addEventListener('message', receiveMessage, false);
+</script>