Standardize usage of virtual/override/final in media/

media/audio/mac/audio_input_mac.h

Index: media/audio/mac/audio_input_mac.h
diff --git a/media/audio/mac/audio_input_mac.h b/media/audio/mac/audio_input_mac.h
index 6c1b4a14f31dc634f7664142d0c5d57e981ba8ef..56453d2eddb1092e0354c530abe2bd4304253aab 100644
--- a/media/audio/mac/audio_input_mac.h
+++ b/media/audio/mac/audio_input_mac.h
@@ -26,19 +26,19 @@ class PCMQueueInAudioInputStream : public AudioInputStream {
   // Parameters as per AudioManager::MakeAudioInputStream.
   PCMQueueInAudioInputStream(AudioManagerMac* manager,
                              const AudioParameters& params);
-  virtual ~PCMQueueInAudioInputStream();
+  ~PCMQueueInAudioInputStream() override;
 
   // Implementation of AudioInputStream.
-  virtual bool Open() override;
-  virtual void Start(AudioInputCallback* callback) override;
-  virtual void Stop() override;
-  virtual void Close() override;
-  virtual double GetMaxVolume() override;
-  virtual void SetVolume(double volume) override;
-  virtual double GetVolume() override;
-  virtual void SetAutomaticGainControl(bool enabled) override;
-  virtual bool GetAutomaticGainControl() override;
-  virtual bool IsMuted() override;
+  bool Open() override;
+  void Start(AudioInputCallback* callback) override;
+  void Stop() override;
+  void Close() override;
+  double GetMaxVolume() override;
+  void SetVolume(double volume) override;
+  double GetVolume() override;
+  void SetAutomaticGainControl(bool enabled) override;
+  bool GetAutomaticGainControl() override;
+  bool IsMuted() override;
 
  private:
   // Issue the OnError to |callback_|;