Standardize usage of virtual/override/final in media/

media/audio/virtual_audio_output_stream.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 MEDIA_AUDIO_VIRTUAL_AUDIO_OUTPUT_STREAM_H_
 #define MEDIA_AUDIO_VIRTUAL_AUDIO_OUTPUT_STREAM_H_
 
 #include "base/callback.h"
 #include "base/threading/thread_checker.h"
 #include "media/audio/audio_io.h"
@@ skipping 16 matching lines @@
   // Callback invoked just after VirtualAudioOutputStream is closed.
   typedef base::Callback<void(VirtualAudioOutputStream* vaos)>
       AfterCloseCallback;
 
   // Construct an audio loopback pathway to the given |target| (not owned).
   // |target| must outlive this instance.
   VirtualAudioOutputStream(const AudioParameters& params,
                            VirtualAudioInputStream* target,
                            const AfterCloseCallback& after_close_cb);
 
-  virtual ~VirtualAudioOutputStream();
+  ~VirtualAudioOutputStream() override;
 
   // AudioOutputStream:
-  virtual bool Open() override;
-  virtual void Start(AudioSourceCallback* callback) override;
-  virtual void Stop() override;
-  virtual void SetVolume(double volume) override;
-  virtual void GetVolume(double* volume) override;
-  virtual void Close() override;
+  bool Open() override;
+  void Start(AudioSourceCallback* callback) override;
+  void Stop() override;
+  void SetVolume(double volume) override;
+  void GetVolume(double* volume) override;
+  void Close() override;
 
  private:
   // AudioConverter::InputCallback:
-  virtual double ProvideInput(AudioBus* audio_bus,
-                              base::TimeDelta buffer_delay) override;
+  double ProvideInput(AudioBus* audio_bus,
+                      base::TimeDelta buffer_delay) override;
 
   const AudioParameters params_;
   // Pointer to the VirtualAudioInputStream to attach to when Start() is called.
   // This pointer should always be valid because VirtualAudioInputStream should
   // outlive this class.
   VirtualAudioInputStream* const target_input_stream_;
 
   AfterCloseCallback after_close_cb_;
 
   AudioSourceCallback* callback_;
   double volume_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(VirtualAudioOutputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_VIRTUAL_AUDIO_OUTPUT_STREAM_H_