Enable automatic audio playback device switching (#92)

Author: taste1981

modules/audio_device/win/audio_device_core_win.cc

@@ -184,11 +184,13 @@ HRESULT __stdcall AudioDeviceWindowsCore::OnDefaultDeviceChanged(
 
 ULONG AudioDeviceWindowsCore::AddRef() {
   ULONG new_ref = InterlockedIncrement(&ref_count_);
+  // RTC_DLOG(INFO) << "__AddRef => " << new_ref;
   return new_ref;
 }
 
 ULONG AudioDeviceWindowsCore::Release() {
   ULONG new_ref = InterlockedDecrement(&ref_count_);
+  // RTC_DLOG(INFO) << "__Release => " << new_ref;
   return new_ref;
 }
 
@@ -404,7 +406,6 @@ AudioDeviceWindowsCore::AudioDeviceWindowsCore()
       _hRecThread(nullptr),
       _hCaptureStartedEvent(nullptr),
       _hShutdownCaptureEvent(nullptr),
-      _hDeviceRestartEvent(nullptr),
       _hMmTask(nullptr),
       _playAudioFrameSize(0),
       _playSampleRate(0),