PPAPI: Implement synchronous postMessage

ppapi/proxy/ppb_message_loop_proxy.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_
 #define PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
@@ skipping 26 matching lines @@
   virtual int32_t PostWork(PP_CompletionCallback callback,
                            int64_t delay_ms) OVERRIDE;
   virtual int32_t PostQuit(PP_Bool should_destroy) OVERRIDE;
 
   static MessageLoopResource* GetCurrent();
   void DetachFromThread();
   bool is_main_thread_loop() const {
     return is_main_thread_loop_;
   }
 
+  const scoped_refptr<base::MessageLoopProxy>& message_loop_proxy() {
+    return loop_proxy_;
+  }
+
  private:
   struct TaskInfo {
     tracked_objects::Location from_here;
     base::Closure closure;
     int64 delay_ms;
   };
 
   // Returns true if the object is associated with the current thread.
   bool IsCurrent() const;
 
@@ skipping 47 matching lines @@
   static const PPB_MessageLoop_1_0* GetInterface();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PPB_MessageLoop_Proxy);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_