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..9c1a27350c10a153c9e10bc0a6d519656a801984 100644
--- a/media/audio/win/audio_manager_win.h
+++ b/media/audio/win/audio_manager_win.h
@@ -12,16 +12,20 @@
 #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 {
 
 // Windows implementation of the AudioManager singleton. This class is internal
 // to the audio output and only internal users can call methods not exposed by
 // the AudioManager class.
-class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
+class MEDIA_EXPORT AudioManagerWin
+    : public AudioManagerBase,
+      NON_EXPORTED_BASE(public AudioManager::AudioDeviceListener) {
  public:
   AudioManagerWin();
   // Implementation of AudioManager.
+  virtual void Init() OVERRIDE;
   virtual bool HasAudioOutputDevices() OVERRIDE;
   virtual bool HasAudioInputDevices() OVERRIDE;
   virtual string16 GetAudioInputDeviceModel() OVERRIDE;
@@ -42,6 +46,9 @@ class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
   virtual AudioParameters GetPreferredLowLatencyOutputStreamParameters(
       const AudioParameters& input_params) OVERRIDE;
 
+  // AudioDeviceListener implementation.
+  virtual void OnDeviceChange() OVERRIDE;
+
  protected:
   virtual ~AudioManagerWin();
 
@@ -70,6 +77,9 @@ class MEDIA_EXPORT AudioManagerWin : public AudioManagerBase {
       const AudioParameters& params,
       const std::string& device_id);
 
+  // Listen for output device changes.
+  scoped_ptr<AudioDeviceListenerWin> output_device_listener_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioManagerWin);
 };