Replace AudioSilenceDetector with an AudioPowerMonitor.

media/audio/audio_output_controller.h

Index: media/audio/audio_output_controller.h
diff --git a/media/audio/audio_output_controller.h b/media/audio/audio_output_controller.h
index dddb90e368ef25fd02155a30bc392dd27d09d895..54b5637216c384015bf31d5a758818467ea4dc50 100644
--- a/media/audio/audio_output_controller.h
+++ b/media/audio/audio_output_controller.h
@@ -52,7 +52,7 @@
 
 namespace media {
 
-class AudioSilenceDetector;
+class AudioPowerMonitor;
 
 class MEDIA_EXPORT AudioOutputController
     : public base::RefCountedThreadSafe<AudioOutputController>,
@@ -66,7 +66,7 @@ class MEDIA_EXPORT AudioOutputController
    public:
     virtual void OnCreated() = 0;
     virtual void OnPlaying() = 0;
-    virtual void OnAudible(bool is_audible) = 0;
+    virtual void OnPowerMeasured(float power_dbfs, bool clipped) = 0;
     virtual void OnPaused() = 0;
     virtual void OnError() = 0;
     virtual void OnDeviceChange(int new_buffer_size, int new_sample_rate) = 0;
@@ -175,7 +175,7 @@ class MEDIA_EXPORT AudioOutputController
   void DoCreate(bool is_for_device_change);
   void DoPlay();
   void DoPause();
-  void DoClose();
+  void DoClose(const base::Closure& done_callback);
   void DoSetVolume(double volume);
   void DoReportError();
   void DoStartDiverting(AudioOutputStream* to_stream);
@@ -234,9 +234,9 @@ class MEDIA_EXPORT AudioOutputController
   int number_polling_attempts_left_;
 
   // Scans audio samples from OnMoreIOData() as input and causes
-  // EventHandler::OnAudbile() to be called whenever a transition to a period of
-  // silence or non-silence is detected.
-  scoped_ptr<AudioSilenceDetector> silence_detector_;
+  // EventHandler::OnPowerMeasured() to be called with power level measurements
+  // at regular intervals.
+  scoped_ptr<AudioPowerMonitor> power_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioOutputController);
 };