Add OVERRIDE to media/.

media/audio/mac/audio_low_latency_output_mac.h

 // Copyright (c) 2011 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.
 //
 // Implementation notes:
 //
 // - It is recommended to first acquire the native sample rate of the default
 //   output device and then use the same rate when creating this object.
 //   Use AUAudioOutputStream::HardwareSampleRate() to retrieve the sample rate.
 // - Calling Close() also leads to self destruction.
@@ skipping 21 matching lines @@
  public:
   // The ctor takes all the usual parameters, plus |manager| which is the
   // the audio manager who is creating this object.
   AUAudioOutputStream(AudioManagerMac* manager,
                       const AudioParameters& params);
   // The dtor is typically called by the AudioManager only and it is usually
   // triggered by calling AudioOutputStream::Close().
   virtual ~AUAudioOutputStream();
 
   // Implementation of AudioOutputStream.
-  virtual bool Open();
-  virtual void Close();
-  virtual void Start(AudioSourceCallback* callback);
-  virtual void Stop();
-  virtual void SetVolume(double volume);
-  virtual void GetVolume(double* volume);
+  virtual bool Open() OVERRIDE;
+  virtual void Close() OVERRIDE;
+  virtual void Start(AudioSourceCallback* callback) OVERRIDE;
+  virtual void Stop() OVERRIDE;
+  virtual void SetVolume(double volume) OVERRIDE;
+  virtual void GetVolume(double* volume) OVERRIDE;
 
   static double HardwareSampleRate();
 
  private:
   // DefaultOutputUnit callback.
   static OSStatus InputProc(void* user_data,
                             AudioUnitRenderActionFlags* flags,
                             const AudioTimeStamp* time_stamp,
                             UInt32 bus_number,
                             UInt32 number_of_frames,
@@ skipping 32 matching lines @@
   // Volume level from 0 to 1.
   float volume_;
 
   // Fixed playout hardware latency in frames.
   double hardware_latency_frames_;
 
   DISALLOW_COPY_AND_ASSIGN(AUAudioOutputStream);
 };
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_OUTPUT_MAC_H_