PPAPI: Add dev synchronous JS->Plugin messaging API

content/renderer/pepper/pepper_plugin_instance_impl.h

Index: content/renderer/pepper/pepper_plugin_instance_impl.h
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.h b/content/renderer/pepper/pepper_plugin_instance_impl.h
index 9d067a94a0e51ca5e9623c02398ae02cc0f529f4..c4874bf578107aaf0aedd6d8702c8488ef5a5ccc 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.h
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.h
@@ -411,6 +411,11 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
                                  double minimum_factor,
                                  double maximum_factor) OVERRIDE;
   virtual void PostMessage(PP_Instance instance, PP_Var message) OVERRIDE;
+  virtual int32_t RegisterMessageHandler(PP_Instance instance,
+                                         void* user_data,
+                                         const PPP_MessageHandler_0_1* handler,
+                                         PP_Resource message_loop) OVERRIDE;
+  virtual void UnregisterMessageHandler(PP_Instance instance) OVERRIDE;
   virtual PP_Bool SetCursor(PP_Instance instance,
                             PP_MouseCursor_Type type,
                             PP_Resource image,