Work around for HDMI audio output rediscovering transistion loss.

ash/system/win/audio/tray_audio_delegate_win.cc

Index: ash/system/win/audio/tray_audio_delegate_win.cc
diff --git a/ash/system/win/audio/tray_audio_delegate_win.cc b/ash/system/win/audio/tray_audio_delegate_win.cc
index 18e46af3bdd968f68c6f17d76367beef154eb7d8..2b6095a1fae6bef1574d78433a30f3ee74729f89 100644
--- a/ash/system/win/audio/tray_audio_delegate_win.cc
+++ b/ash/system/win/audio/tray_audio_delegate_win.cc
@@ -96,6 +96,10 @@ void TrayAudioDelegateWin::SetInternalSpeakerChannelMode(
     AudioChannelMode mode) {
 }
 
+void TrayAudioDelegateWin::SetActiveHDMIOutoutRediscoveringIfNecessary(
+    bool force_rediscovering) {
+}
+
 ScopedComPtr<ISimpleAudioVolume>
 TrayAudioDelegateWin::CreateDefaultVolumeControl() {
   ScopedComPtr<ISimpleAudioVolume> volume_control;