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

media/audio/audio_manager_base.h

Index: media/audio/audio_manager_base.h
diff --git a/media/audio/audio_manager_base.h b/media/audio/audio_manager_base.h
index bc13ee5a1677b46c89d08d47321b23bcd59606d8..84a964467647b7cd11dcee0a6fd51b6b2feeff41 100644
--- a/media/audio/audio_manager_base.h
+++ b/media/audio/audio_manager_base.h
@@ -102,6 +102,10 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   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;
@@ -135,6 +139,8 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   // 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();
@@ -179,6 +185,9 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   // 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_;