Log audio system used to WebRTC log.

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 89e9eab41d51cb260ae8dfecf65263fed14e7cc0..21f15cdcd4952aeab5ab3c7a70c2db445e22cacf 100644
--- a/media/audio/win/audio_manager_win.cc
+++ b/media/audio/win/audio_manager_win.cc
@@ -331,6 +331,10 @@ std::string AudioManagerWin::GetAssociatedOutputDeviceID(
   return CoreAudioUtil::GetMatchingOutputDeviceID(input_device_id);
 }
 
+const char* AudioManagerWin::GetName() {
+  return "Windows";
+}
+
 // Factory for the implementations of AudioOutputStream for AUDIO_PCM_LINEAR
 // mode.
 // - PCMWaveOutAudioOutputStream: Based on the waveOut API.