Support using TrackedCallbacks as hints to determine the handling thread of resource reply messages

ppapi/proxy/ppb_message_loop_proxy.cc

 // 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.
 
 #include "ppapi/proxy/ppb_message_loop_proxy.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 171 matching lines @@
         from_here, closure, base::TimeDelta::FromMilliseconds(delay_ms));
   } else {
     TaskInfo info;
     info.from_here = FROM_HERE;
     info.closure = closure;
     info.delay_ms = delay_ms;
     pending_tasks_.push_back(info);
   }
 }
 
+base::MessageLoopProxy* MessageLoopResource::GetMessageLoopProxy() {
+  return loop_proxy_.get();
+}
+
 // static
 void MessageLoopResource::ReleaseMessageLoop(void* value) {
   static_cast<MessageLoopResource*>(value)->DetachFromThread();
 }
 
 // -----------------------------------------------------------------------------
 
 PP_Resource Create(PP_Instance instance) {
   ProxyAutoLock lock;
   // Validate the instance.
@@ skipping 63 matching lines @@
 PPB_MessageLoop_Proxy::~PPB_MessageLoop_Proxy() {
 }
 
 // static
 const PPB_MessageLoop_1_0* PPB_MessageLoop_Proxy::GetInterface() {
   return &ppb_message_loop_interface;
 }
 
 }  // namespace proxy
 }  // namespace ppapi