A proposal and implementation for an initial postMessage interface. These in...

webkit/plugins/ppapi/ppapi_plugin_instance.h

Index: webkit/plugins/ppapi/ppapi_plugin_instance.h
===================================================================
--- webkit/plugins/ppapi/ppapi_plugin_instance.h	(revision 78910)
+++ webkit/plugins/ppapi/ppapi_plugin_instance.h	(working copy)
@@ -29,9 +29,11 @@
 struct PPB_Instance;
 struct PPB_Find_Dev;
 struct PPB_Fullscreen_Dev;
+struct PPB_Messaging_Dev;
 struct PPB_Zoom_Dev;
 struct PPP_Find_Dev;
 struct PPP_Instance;
+struct PPP_Messaging_Dev;
 struct PPP_Pdf;
 struct PPP_Selection_Dev;
 struct PPP_Zoom_Dev;
@@ -53,6 +55,7 @@
 namespace ppapi {
 
 class FullscreenContainer;
+class MessageChannel;
 class ObjectVar;
 class PluginDelegate;
 class PluginModule;
@@ -80,10 +83,12 @@
   // exposed to the plugin.
   static const PPB_Find_Dev* GetFindInterface();
   static const PPB_Fullscreen_Dev* GetFullscreenInterface();
+  static const PPB_Messaging_Dev* GetMessagingInterface();
   static const PPB_Zoom_Dev* GetZoomInterface();
 
   PluginDelegate* delegate() const { return delegate_; }
   PluginModule* module() const { return module_.get(); }
+  MessageChannel& message_channel() { return *message_channel_; }
 
   WebKit::WebPluginContainer* container() const { return container_; }
 
@@ -210,6 +215,11 @@
   // Implementation of PPB_Flash.
   bool NavigateToURL(const char* url, const char* target);
 
+  // Implementation of PPB_Messaging.

[brettw, 2011/03/22 05:59:11]

I'd just use one comment for both of these functions. I don't think
"Implementation" is too misleading here, even though one of the functions is an
override. If this offends you, sometimes some people just write "//
PPP_Messanging."

+  void PostMessage(PP_Var message);
+  // Passthrough for PPP_Messaging.
+  void HandleMessage(PP_Var message);
+
   PluginDelegate::PlatformContext3D* CreateContext3D();
 
   // Tracks all live ObjectVar. This is so we can map between PluginModule +
@@ -230,6 +240,7 @@
 
  private:
   bool LoadFindInterface();
+  bool LoadMessagingInterface();
   bool LoadPdfInterface();
   bool LoadSelectionInterface();
   bool LoadZoomInterface();
@@ -315,6 +326,7 @@
 
   // The plugin-provided interfaces.
   const PPP_Find_Dev* plugin_find_interface_;
+  const PPP_Messaging_Dev* plugin_messaging_interface_;
   const PPP_Pdf* plugin_pdf_interface_;
   const PPP_Selection_Dev* plugin_selection_interface_;
   const PPP_Zoom_Dev* plugin_zoom_interface_;
@@ -363,6 +375,10 @@
   // True if we are in fullscreen mode. Note: it is false during the transition.
   bool fullscreen_;
 
+  // The MessageChannel used to implement bidirectional postMessage for the
+  // instance.
+  scoped_ptr<MessageChannel> message_channel_;
+
   // Bitmap for crashed plugin. Lazily initialized, non-owning pointer.
   SkBitmap* sad_plugin_;