Handle audio device changes on Windows.

media/audio/win/audio_manager_win.cc

Index: media/audio/win/audio_manager_win.cc
diff --git a/media/audio/win/audio_manager_win.cc b/media/audio/win/audio_manager_win.cc
index 4449d150d14019ae05a71f8aa2d8b77642cd5638..ced605fa44bc2ca3ed42c117bbbcdac0af2f2d11 100644
--- a/media/audio/win/audio_manager_win.cc
+++ b/media/audio/win/audio_manager_win.cc
@@ -10,6 +10,8 @@
 #include <mmsystem.h>
 #include <setupapi.h>
 
+#include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
@@ -123,6 +125,11 @@ bool AudioManagerWin::HasAudioInputDevices() {
   return (::waveInGetNumDevs() != 0);
 }
 
+void AudioManagerWin::Init() {
+  AudioManagerBase::Init();
+  output_device_listener_.reset(new AudioDeviceListenerWin(this));
+}
+
 string16 AudioManagerWin::GetAudioInputDeviceModel() {
   // Get the default audio capture device and its device interface name.
   DWORD device_id = 0;
@@ -345,4 +352,10 @@ AudioParameters AudioManagerWin::GetPreferredLowLatencyOutputStreamParameters(
       sample_rate, bits_per_sample, GetAudioHardwareBufferSize());
 }
 
+void AudioManagerWin::OnDeviceChange() {
+  GetMessageLoop()->PostTask(FROM_HERE, base::Bind(
+      &AudioManagerWin::NotifyAllOutputDeviceChangeListeners,
+      base::Unretained(this)));
+}
+
 }  // namespace media