Browser Plugin: Add HTML5-like postMessage support

content/renderer/browser_plugin/browser_plugin.cc

Index: content/renderer/browser_plugin/browser_plugin.cc
diff --git a/content/renderer/browser_plugin/browser_plugin.cc b/content/renderer/browser_plugin/browser_plugin.cc
index 712c41a93f060738323e498f6fa612bbd476bcd5..abee6b87a34bf82fc148554fe64c4945cdcc42cc 100644
--- a/content/renderer/browser_plugin/browser_plugin.cc
+++ b/content/renderer/browser_plugin/browser_plugin.cc
@@ -64,7 +64,8 @@ BrowserPlugin::BrowserPlugin(
       resize_pending_(false),
       navigate_src_sent_(false),
       process_id_(-1),
-      persist_storage_(false) {
+      persist_storage_(false),
+      guest_routing_id_(MSG_ROUTING_NONE) {
   BrowserPluginManager::Get()->AddBrowserPlugin(instance_id, this);
   bindings_.reset(new BrowserPluginBindings(this));
 
@@ -132,6 +133,15 @@ void BrowserPlugin::SetSrcAttribute(const std::string& src) {
   guest_crashed_ = false;
 }
 
+NPObject* BrowserPlugin::GetContentWindow() const {
+  if (guest_routing_id_ == MSG_ROUTING_NONE)
+    return NULL;
+  RenderViewImpl* guest_render_view = static_cast<RenderViewImpl*>(
+    ChildThread::current()->ResolveRoute(guest_routing_id_));
+  WebKit::WebFrame* guest_frame = guest_render_view->GetWebView()->mainFrame();
+  return guest_frame->windowObject();
+}
+
 std::string BrowserPlugin::GetPartitionAttribute() const {
   std::string value;
   if (persist_storage_)
@@ -348,6 +358,42 @@ void BrowserPlugin::AdvanceFocus(bool reverse) {
     render_view_->GetWebView()->advanceFocus(reverse);
 }
 
+void BrowserPlugin::ReceiveMessage(int source_routing_id,
+                                   const string16& source_origin,
+                                   int source_frame_id,
+                                   const string16& data) {
+  // This is a swapped out RenderViewImpl for the guest in the embedder process.

[nasko, 2012/10/02 17:52:31]

If this is the case, can we DCHECK that it is indeed swapped out?

[Fady Samuel, 2012/10/02 22:04:08]

Done.

+  WebKit::WebFrame* source_frame = NULL;
+  if (source_routing_id != MSG_ROUTING_NONE) {
+    RenderViewImpl* source_render_view = static_cast<RenderViewImpl*>(
+      ChildThread::current()->ResolveRoute(source_routing_id));
+    if (source_render_view) {
+      source_frame = source_render_view->GetFrameByMappedID(
+          source_frame_id);
+    }
+  }
+  WebKit::WebFrame* target_frame = render_view_->webview()->mainFrame();

[nasko, 2012/10/02 17:52:31]

Why are we using the top level frame as the target? Doesn't the browser plugin
have its own frame that we should be targeting?

[Fady Samuel, 2012/10/02 22:04:08]

I'm not sure it matters? We only use target_frame to create the MessageEvent
object.

+  WebKit::WebDOMEvent event =
+      target_frame->document().createEvent("MessageEvent");
+  WebKit::WebDOMMessageEvent msg_event = event.to<WebKit::WebDOMMessageEvent>();
+  msg_event.initMessageEvent("message",
+                             // |canBubble| and |cancellable| are always false
+                             false, false,
+                             WebKit::WebSerializedScriptValue::fromString(data),
+                             source_origin, source_frame, "");
+  // TODO(fsamuel): Does it make sense to do an origin check here? When
+  // the guest replies back to the embedder, the embedder cannot possibly
+  // navigate away to a different origin because the guest's lifetime
+  // is tied to the embedder's lifetime. If the embedder navigates away,
+  // the guest is cleaned up.
+  container()->element().dispatchEvent(msg_event);
+}
+
+void BrowserPlugin::GuestContentWindowReady(int guest_routing_id) {
+  DCHECK(guest_routing_id != MSG_ROUTING_NONE);
+  guest_routing_id_ = guest_routing_id;
+}
+
 void BrowserPlugin::SetAcceptTouchEvents(bool accept) {
   if (container())
     container()->setIsAcceptingTouchEvents(accept);