Improve logging related to start/stop and failure of audio input streams in Chrome

media/audio/audio_manager_base.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_MANAGER_BASE_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
 
 #include <string>
 #include <utility>
 
@@ skipping 84 matching lines @@
   // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
   virtual AudioInputStream* MakeLowLatencyInputStream(
       const AudioParameters& params, const std::string& device_id) = 0;
 
   // Listeners will be notified on the GetTaskRunner() task runner.
   virtual void AddOutputDeviceChangeListener(
       AudioDeviceListener* listener) OVERRIDE;
   virtual void RemoveOutputDeviceChangeListener(
       AudioDeviceListener* listener) OVERRIDE;
 
+  virtual void AddStateChangeListener(StateChangeListener* listener) OVERRIDE;
+  virtual void RemoveStateChangeListener(
+      StateChangeListener* listener) OVERRIDE;
+
   virtual AudioParameters GetDefaultOutputStreamParameters() OVERRIDE;
   virtual AudioParameters GetOutputStreamParameters(
       const std::string& device_id) OVERRIDE;
 
   virtual AudioParameters GetInputStreamParameters(
       const std::string& device_id) OVERRIDE;
 
   virtual std::string GetAssociatedOutputDeviceID(
       const std::string& input_device_id) OVERRIDE;
 
@@ skipping 13 matching lines @@
   // implementation.
   void Shutdown();
 
   void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
 
   // Called by each platform specific AudioManager to notify output state change
   // listeners that a state change has occurred.  Must be called from the audio
   // thread.
   void NotifyAllOutputDeviceChangeListeners();
 
+  void NotifyAllStateChangeListeners(const std::string& msg);
+
   // Returns user buffer size as specified on the command line or 0 if no buffer
   // size has been specified.
   int GetUserBufferSize();
 
   // Returns the preferred hardware audio output parameters for opening output
   // streams. If the users inject a valid |input_params|, each AudioManager
   // will decide if they should return the values from |input_params| or the
   // default hardware values. If the |input_params| is invalid, it will return
   // the default hardware audio parameters.
   // If |output_device_id| is empty, the implementation must treat that as
@@ skipping 24 matching lines @@
 
   // Number of currently open output streams.
   int num_output_streams_;
 
   // Number of currently open input streams.
   int num_input_streams_;
 
   // Track output state change listeners.
   ObserverList<AudioDeviceListener> output_listeners_;
 
+  // Track .....
+  ObserverList<StateChangeListener> state_listeners_;
+
   // Thread used to interact with audio streams created by this audio manager.
   base::Thread audio_thread_;
 
   // The task runner of the audio thread this object runs on. Used for internal
   // tasks which run on the audio thread even after Shutdown() has been started
   // and GetTaskRunner() starts returning NULL.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // Map of cached AudioOutputDispatcher instances.  Must only be touched
   // from the audio thread (no locking).
   AudioOutputDispatchers output_dispatchers_;
 
   // Proxy for creating AudioLog objects.
   AudioLogFactory* const audio_log_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_