PPAPI: Get TrackedCallback ready for running on non-main threads.

ppapi/proxy/ppb_file_system_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_file_system_proxy.h"
 
 #include "base/bind.h"
 #include "base/message_loop.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_file_system.h"
@@ skipping 76 matching lines @@
       new PpapiHostMsg_PPBFileSystem_Open(
           API_ID_PPB_FILE_SYSTEM, host_resource(), expected_size));
   return PP_OK_COMPLETIONPENDING;
 }
 
 PP_FileSystemType FileSystem::GetType() {
   return type_;
 }
 
 void FileSystem::OpenComplete(int32_t result) {
-  TrackedCallback::ClearAndRun(&current_open_callback_, result);
+  current_open_callback_->Run(result);
 }
 
 PPB_FileSystem_Proxy::PPB_FileSystem_Proxy(Dispatcher* dispatcher)
     : InterfaceProxy(dispatcher),
       callback_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
 }
 
 PPB_FileSystem_Proxy::~PPB_FileSystem_Proxy() {
 }
 
@@ skipping 67 matching lines @@
 
 void PPB_FileSystem_Proxy::OpenCompleteInHost(
     int32_t result,
     const HostResource& host_resource) {
   dispatcher()->Send(new PpapiMsg_PPBFileSystem_OpenComplete(
       API_ID_PPB_FILE_SYSTEM, host_resource, result));
 }
 
 }  // namespace proxy
 }  // namespace ppapi