Update {virtual,override} to follow C++11 style in ppapi.

ppapi/proxy/media_stream_audio_track_resource.h

 // Copyright 2014 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_MEDIA_STREAM_AUDIO_TRACK_RESOURCE_H_
 #define PPAPI_PROXY_MEDIA_STREAM_AUDIO_TRACK_RESOURCE_H_
 
 #include <map>
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "ppapi/proxy/media_stream_track_resource_base.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 #include "ppapi/thunk/ppb_media_stream_audio_track_api.h"
 
 namespace ppapi {
 namespace proxy {
 
 class AudioBufferResource;
 
 class PPAPI_PROXY_EXPORT MediaStreamAudioTrackResource
     : public MediaStreamTrackResourceBase,
       public thunk::PPB_MediaStreamAudioTrack_API {
  public:
   MediaStreamAudioTrackResource(Connection connection,
                                 PP_Instance instance,
                                 int pending_renderer_id,
                                 const std::string& id);
 
-  virtual ~MediaStreamAudioTrackResource();
+  ~MediaStreamAudioTrackResource() override;
 
   // Resource overrides:
-  virtual thunk::PPB_MediaStreamAudioTrack_API*
-  AsPPB_MediaStreamAudioTrack_API() override;
+  thunk::PPB_MediaStreamAudioTrack_API* AsPPB_MediaStreamAudioTrack_API()
+      override;
 
   // PPB_MediaStreamAudioTrack_API overrides:
-  virtual PP_Var GetId() override;
-  virtual PP_Bool HasEnded() override;
-  virtual int32_t Configure(const int32_t attrib_list[],
-                            scoped_refptr<TrackedCallback> callback) override;
-  virtual int32_t GetAttrib(PP_MediaStreamAudioTrack_Attrib attrib,
-                            int32_t* value) override;
-  virtual int32_t GetBuffer(
-      PP_Resource* buffer,
-      scoped_refptr<TrackedCallback> callback) override;
-  virtual int32_t RecycleBuffer(PP_Resource buffer) override;
-  virtual void Close() override;
+  PP_Var GetId() override;
+  PP_Bool HasEnded() override;
+  int32_t Configure(const int32_t attrib_list[],
+                    scoped_refptr<TrackedCallback> callback) override;
+  int32_t GetAttrib(PP_MediaStreamAudioTrack_Attrib attrib,
+                    int32_t* value) override;
+  int32_t GetBuffer(PP_Resource* buffer,
+                    scoped_refptr<TrackedCallback> callback) override;
+  int32_t RecycleBuffer(PP_Resource buffer) override;
+  void Close() override;
 
   // MediaStreamBufferManager::Delegate overrides:
-  virtual void OnNewBufferEnqueued() override;
+  void OnNewBufferEnqueued() override;
 
  private:
   PP_Resource GetAudioBuffer();
 
   void ReleaseBuffers();
 
   // IPC message handlers.
   void OnPluginMsgConfigureReply(const ResourceMessageReplyParams& params);
 
   // Allocated buffer resources by |GetBuffer()|.
   typedef std::map<PP_Resource, scoped_refptr<AudioBufferResource> > BufferMap;
   BufferMap buffers_;
 
   PP_Resource* get_buffer_output_;
 
   scoped_refptr<TrackedCallback> configure_callback_;
 
   scoped_refptr<TrackedCallback> get_buffer_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamAudioTrackResource);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_MEDIA_STREAM_AUDIO_TRACK_RESOURCE_H_