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..b1110b36d83025e1774cad765a2ddb3a050c0764 100644
--- a/media/audio/win/audio_manager_win.cc
+++ b/media/audio/win/audio_manager_win.cc
@@ -10,10 +10,13 @@
 #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"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_number_conversions.h"
@@ -123,6 +126,11 @@ bool AudioManagerWin::HasAudioInputDevices() {
   return (::waveInGetNumDevs() != 0);
 }
 
+void AudioManagerWin::InitializeOnAudioThread() {
+  // AudioDeviceListenerWin must be initialized on a COM thread.
+  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 +353,14 @@ AudioParameters AudioManagerWin::GetPreferredLowLatencyOutputStreamParameters(
       sample_rate, bits_per_sample, GetAudioHardwareBufferSize());
 }
 
+void AudioManagerWin::OnDeviceChange() {
+  // Only fire device changes if low latency output is supported.
+  if (!media::IsWASAPISupported())

[scherkus (not reviewing), 2012/10/24 04:27:09]

This is impossible because your check for the equivalent statement when creating
ADLWin during creation.

I'd like to isolate WASAPI/Vista-checking code to the managers if at all
possible.

How about:
  * ADLWin documents + CHECK()s we're on the right OS
  * AMWin doesn't create an ADLWin if we're not on the right OS
  * This method DCHECKs

[DaleCurtis, 2012/10/24 19:27:29]

Done.

+    return;
+
+  GetMessageLoop()->PostTask(FROM_HERE, base::Bind(
+      &AudioManagerWin::NotifyAllOutputDeviceChangeListeners,
+      base::Unretained(this)));
+}
+
 }  // namespace media