Pepper: Introduce ThreadAwareCallback.

ppapi/proxy/device_enumeration_resource_helper.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_DEVICE_ENUMERATION_RESOURCE_HELPER_H_
 #define PPAPI_PROXY_DEVICE_ENUMERATION_RESOURCE_HELPER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "ppapi/c/dev/ppb_device_ref_dev.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
+#include "ppapi/shared_impl/thread_aware_callback.h"
 
 namespace IPC {
 class Message;
 }
 
 struct PP_ArrayOutput;
 
 namespace ppapi {
 
 struct DeviceRefData;
@@ skipping 42 matching lines @@
 
   int32_t WriteToArrayOutput(const std::vector<DeviceRefData>& devices,
                              const PP_ArrayOutput& output);
 
   // Not owned by this object.
   PluginResource* owner_;
 
   bool pending_enumerate_devices_;
 
   uint32_t monitor_callback_id_;
-  PP_MonitorDeviceChangeCallback monitor_callback_;
+  scoped_ptr<ThreadAwareCallback<PP_MonitorDeviceChangeCallback> >
+      monitor_callback_;
   void* monitor_user_data_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceEnumerationResourceHelper);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_DEVICE_ENUMERATION_RESOURCE_HELPER_H_