Only log audio input silence state UMA stats for low latency mode and if not fake device.

media/audio/audio_input_controller.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_AUDIO_INPUT_CONTROLLER_H_
 #define MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_
 
 #include <string>
 #include "base/atomicops.h"
 #include "base/callback.h"
@@ skipping 173 matching lines @@
   // thread. |user_input_monitor| is used for typing detection and can be NULL.
   static scoped_refptr<AudioInputController> CreateLowLatency(
       AudioManager* audio_manager,
       EventHandler* event_handler,
       const AudioParameters& params,
       const std::string& device_id,
       // External synchronous writer for audio controller.
       SyncWriter* sync_writer,
       UserInputMonitor* user_input_monitor);
 
-  // Factory method for creating an AudioInputController for low-latency mode,
-  // taking ownership of |stream|.  The stream will be opened on the audio
-  // thread, and when that is done, the event handler will receive an
-  // OnCreated() call from that same thread. |user_input_monitor| is used for
-  // typing detection and can be NULL.
+  // Factory method for creating an AudioInputController with an existing
+  // |stream| for low-latency mode, taking ownership of |stream|. The stream
+  // will be opened on the audio thread, and when that is done, the event
+  // handler will receive an OnCreated() call from that same thread.
+  // |user_input_monitor| is used for typing detection and can be NULL.
   static scoped_refptr<AudioInputController> CreateForStream(
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       EventHandler* event_handler,
       AudioInputStream* stream,
       // External synchronous writer for audio controller.
       SyncWriter* sync_writer,
       UserInputMonitor* user_input_monitor);
 
   // Starts recording using the created audio input stream.
   // This method is called on the creator thread.
@@ skipping 35 matching lines @@
     CREATED,
     RECORDING,
     CLOSED
   };
 
 #if defined(AUDIO_POWER_MONITORING)
   // Used to log a silence report (see OnData).
   // Elements in this enum should not be deleted or rearranged; the only
   // permitted operation is to add new elements before SILENCE_STATE_MAX and
   // update SILENCE_STATE_MAX.
+  // Possible silence state transitions:
+  //           SILENCE_STATE_AUDIO_AND_SILENCE
+  //               ^                  ^
+  // SILENCE_STATE_ONLY_AUDIO   SILENCE_STATE_ONLY_SILENCE
+  //               ^                  ^
+  //            SILENCE_STATE_NO_MEASUREMENT
   enum SilenceState {
     SILENCE_STATE_NO_MEASUREMENT = 0,
     SILENCE_STATE_ONLY_AUDIO = 1,
     SILENCE_STATE_ONLY_SILENCE = 2,
     SILENCE_STATE_AUDIO_AND_SILENCE = 3,
     SILENCE_STATE_MAX = SILENCE_STATE_AUDIO_AND_SILENCE
   };
 #endif
 
   AudioInputController(EventHandler* handler,
                        SyncWriter* sync_writer,
                        UserInputMonitor* user_input_monitor);
   virtual ~AudioInputController();
 
   // Methods called on the audio thread (owned by the AudioManager).
   void DoCreate(AudioManager* audio_manager, const AudioParameters& params,
                 const std::string& device_id);
+  void DoCreateForLowLatency(AudioManager* audio_manager,
+                             const AudioParameters& params,
+                             const std::string& device_id);
   void DoCreateForStream(AudioInputStream* stream_to_control);
   void DoRecord();
   void DoClose();
   void DoReportError();
   void DoSetVolume(double volume);
   void DoSetAutomaticGainControl(bool enabled);
   void DoOnData(scoped_ptr<AudioBus> data);
   void DoLogAudioLevel(float level_dbfs);
 
   // Method to check if we get recorded data after a stream was started,
   // and log the result to UMA.
   void FirstCheckForNoData();
 
   // Method which ensures that OnError() is triggered when data recording
   // times out. Called on the audio thread.
   void DoCheckForNoData();
 
   // Helper method that stops, closes, and NULL:s |*stream_|.
   void DoStopCloseAndClearStream();
 
   void SetDataIsActive(bool enabled);
   bool GetDataIsActive();
 
 #if defined(AUDIO_POWER_MONITORING)
+  // Updates the silence state, see enum SilenceState above for state
+  // transitions.
+  void UpdateSilenceState(bool silence);
+
+  // Logs the silence state as UMA stat.
   void LogSilenceState(SilenceState value);
 #endif
 
   // Gives access to the task runner of the creating thread.
   scoped_refptr<base::SingleThreadTaskRunner> creator_task_runner_;
 
   // The task runner of audio-manager thread that this object runs on.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // Contains the AudioInputController::EventHandler which receives state
@@ skipping 33 matching lines @@
   UserInputMonitor* user_input_monitor_;
 
 #if defined(AUDIO_POWER_MONITORING)
   // Scans audio samples from OnData() as input to compute audio levels.
   scoped_ptr<AudioPowerMonitor> audio_level_;
 
   // We need these to be able to feed data to the AudioPowerMonitor.
   media::AudioParameters audio_params_;
   base::TimeTicks last_audio_level_log_time_;
 
+  // Whether the silence state should sent as UMA stat.
+  bool log_silence_state_;
+
   // The silence report sent as UMA stat at the end of a session.
   SilenceState silence_state_;
 #endif
 
   size_t prev_key_down_count_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioInputController);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_