Work around for HDMI audio output rediscovering transistion loss.

ash/system/audio/tray_audio.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/system/audio/tray_audio.h"
 
 #include <cmath>
 
 #include "ash/ash_constants.h"
 #include "ash/display/display_manager.h"
@@ skipping 120 matching lines @@
 }
 
 void TrayAudio::OnActiveOutputNodeChanged() {
   Update();
 }
 
 void TrayAudio::OnActiveInputNodeChanged() {
   Update();
 }
 
+void TrayAudio::ChangeInternalSpeakerChannelMode() {
+  // Swap left/right channel only if it is in Yoga mode.
+  system::TrayAudioDelegate::AudioChannelMode channel_mode =
+      system::TrayAudioDelegate::NORMAL;
+  if (gfx::Display::InternalDisplayId() != gfx::Display::kInvalidDisplayID) {
+    const DisplayInfo& display_info =
+        Shell::GetInstance()->display_manager()->GetDisplayInfo(
+            gfx::Display::InternalDisplayId());
+    if (display_info.GetActiveRotation() == gfx::Display::ROTATE_180)
+      channel_mode = system::TrayAudioDelegate::LEFT_RIGHT_SWAPPED;
+  }
+
+  audio_delegate_->SetInternalSpeakerChannelMode(channel_mode);
+}
+
 void TrayAudio::OnDisplayAdded(const gfx::Display& new_display) {
   if (new_display.id() != gfx::Display::InternalDisplayId())
     return;
   ChangeInternalSpeakerChannelMode();
 }
 
 void TrayAudio::OnDisplayRemoved(const gfx::Display& old_display) {
   if (old_display.id() != gfx::Display::InternalDisplayId())
     return;
   ChangeInternalSpeakerChannelMode();
 }
 
 void TrayAudio::OnDisplayMetricsChanged(const gfx::Display& display,
                                         uint32_t changed_metrics) {
   if (display.id() != gfx::Display::InternalDisplayId())
     return;
 
   if (changed_metrics & gfx::DisplayObserver::DISPLAY_METRIC_ROTATION)
     ChangeInternalSpeakerChannelMode();
 }
 
-void TrayAudio::ChangeInternalSpeakerChannelMode() {
-  // Swap left/right channel only if it is in Yoga mode.
-  system::TrayAudioDelegate::AudioChannelMode channel_mode =
-      system::TrayAudioDelegate::NORMAL;
-  if (gfx::Display::InternalDisplayId() != gfx::Display::kInvalidDisplayID) {
-    const DisplayInfo& display_info =
-        Shell::GetInstance()->display_manager()->GetDisplayInfo(
-            gfx::Display::InternalDisplayId());
-    if (display_info.GetActiveRotation() == gfx::Display::ROTATE_180)
-      channel_mode = system::TrayAudioDelegate::LEFT_RIGHT_SWAPPED;
-  }
-
-  audio_delegate_->SetInternalSpeakerChannelMode(channel_mode);
-}
-
 void TrayAudio::Update() {
   if (tray_view())
       tray_view()->SetVisible(GetInitialVisibility());
   if (volume_view_) {
     volume_view_->SetVolumeLevel(
         static_cast<float>(audio_delegate_->GetOutputVolumeLevel()) / 100.0f);
     volume_view_->Update();
   }
 }
 
 }  // namespace ash