Handle audio device changes on Windows.

media/audio/win/audio_manager_win.h

Index: media/audio/win/audio_manager_win.h
diff --git a/media/audio/win/audio_manager_win.h b/media/audio/win/audio_manager_win.h
index 6a4efcbafbd91b11c3773b3fe3786570904e3f81..21dc345840069270144b379dbd6570ab11a64c49 100644
--- a/media/audio/win/audio_manager_win.h
+++ b/media/audio/win/audio_manager_win.h
@@ -12,6 +12,7 @@
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "media/audio/audio_manager_base.h"
+#include "media/audio/win/audio_device_listener_win.h"
 
 namespace media {
 
@@ -21,6 +22,7 @@ namespace media {
 class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
  public:
   AudioManagerWin();
+
   // Implementation of AudioManager.
   virtual bool HasAudioOutputDevices() OVERRIDE;
   virtual bool HasAudioInputDevices() OVERRIDE;
@@ -45,6 +47,9 @@ class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
  protected:
   virtual ~AudioManagerWin();
 
+  // Implementation of AudioManager.
+  virtual void InitializeOnAudioThread() OVERRIDE;
+
  private:
   enum EnumerationType {
     kUninitializedEnumeration = 0,
@@ -70,6 +75,12 @@ class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
       const AudioParameters& params,
       const std::string& device_id);
 
+  // Called by AudioDeviceListenerWin when a device change occurs.
+  void OnDeviceChange();
+
+  // Listen for output device changes.
+  scoped_ptr<AudioDeviceListenerWin> output_device_listener_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioManagerWin);
 };