Browser Plugin: Add HTML5-like postMessage support

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 645644f4279af87a2a3c216be1155838995cccca..fb042ccb2ebf71203843d246c88082a917ce536b 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3013,8 +3013,10 @@ void WebContentsImpl::RouteMessageEvent(
     RenderViewHost* rvh,
     const ViewMsg_PostMessage_Params& params) {
   // Only deliver the message to the active RenderViewHost if the request
-  // came from a RenderViewHost in the same BrowsingInstance.
-  if (!rvh->GetSiteInstance()->IsRelatedSiteInstance(GetSiteInstance()))
+  // came from a RenderViewHost in the same BrowsingInstance or this WebContents
+  // is dedicated to a browser plugin guest.

[Charlie Reis, 2012/10/12 00:31:43]

nit: or if

This check isn't quite right, but I'm trying to decide if it matters.  This
means an embedder could receive a postMessage from anyone (not just its own
guests), for example.  However, I don't think that will be a risk for apps,
since other pages won't have references to app windows (which don't run in
tabs).

I suppose it's ok to leave, but the comment should be clearer that we make an
exception for embedders and guests because they don't run in normal tabs.

[Fady Samuel, 2012/10/12 18:07:53]

Done.

+  if (!rvh->GetSiteInstance()->IsRelatedSiteInstance(GetSiteInstance()) &&
+      !GetBrowserPluginGuest() && !GetBrowserPluginEmbedder())
     return;
 
   ViewMsg_PostMessage_Params new_params(params);
@@ -3039,8 +3041,13 @@ void WebContentsImpl::RouteMessageEvent(
     }
 
     if (source_contents) {
-      new_params.source_routing_id =
-          source_contents->CreateOpenerRenderViews(GetSiteInstance());
+      if (GetBrowserPluginGuest()) {
+        new_params.source_routing_id =

[Charlie Reis, 2012/10/12 00:31:43]

Please mention that we create a swapped out RV for the embedder in the guest's
process, but intentionally do not expose the embedder's opener chain to it.

[Fady Samuel, 2012/10/12 18:07:53]

Done.

+            source_contents->CreateSwappedOutRenderView(GetSiteInstance());
+      } else {
+        new_params.source_routing_id =
+            source_contents->CreateOpenerRenderViews(GetSiteInstance());
+      }
     } else {
       // We couldn't find it, so don't pass a source frame.
       new_params.source_routing_id = MSG_ROUTING_NONE;
@@ -3143,6 +3150,11 @@ WebPreferences WebContentsImpl::GetWebkitPrefs() {
   return GetWebkitPrefs(GetRenderViewHost(), url);
 }
 
+int WebContentsImpl::CreateSwappedOutRenderView(
+    content::SiteInstance* instance) {
+  return render_manager_.CreateRenderView(instance, MSG_ROUTING_NONE, true);
+}
+
 void WebContentsImpl::OnUserGesture() {
   // Notify observers.
   FOR_EACH_OBSERVER(WebContentsObserver, observers_, DidGetUserGesture());