Flip the left/right speaker when the device is in yoga mode.

ash/system/audio/tray_audio.h

 // 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.
 
 #ifndef ASH_SYSTEM_AUDIO_TRAY_AUDIO_H_
 #define ASH_SYSTEM_AUDIO_TRAY_AUDIO_H_
 
 #include "ash/system/audio/audio_observer.h"
 #include "ash/system/tray/tray_image_item.h"
 #include "base/memory/scoped_ptr.h"
+#include "ui/gfx/display_observer.h"
 
 namespace ash {
 
 namespace system {
 class TrayAudioDelegate;
 }
 
 namespace tray {
 class VolumeView;
 }
 
 class TrayAudio : public TrayImageItem,
-                  public AudioObserver {
+                  public AudioObserver,
+                  public gfx::DisplayObserver {
  public:
   TrayAudio(SystemTray* system_tray,
             scoped_ptr<system::TrayAudioDelegate> audio_delegate);
   virtual ~TrayAudio();
 
   static bool ShowAudioDeviceMenu();
 
  protected:
   virtual void Update();
 
@@ skipping 16 matching lines @@
   virtual bool ShouldHideArrow() const OVERRIDE;
   virtual bool ShouldShowShelf() const OVERRIDE;
 
   // Overridden from AudioObserver.
   virtual void OnOutputVolumeChanged() OVERRIDE;
   virtual void OnOutputMuteChanged() OVERRIDE;
   virtual void OnAudioNodesChanged() OVERRIDE;
   virtual void OnActiveOutputNodeChanged() OVERRIDE;
   virtual void OnActiveInputNodeChanged() OVERRIDE;
 
+  // Overridden from gfx::DisplayObserver.
+  virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE;
+  virtual void OnDisplayRemoved(const gfx::Display& old_display) OVERRIDE;
+  virtual void OnDisplayMetricsChanged(const gfx::Display& display,
+                                       uint32_t changed_metrics) OVERRIDE;
+
+  void ChangeAudioChannelMode();
+
   DISALLOW_COPY_AND_ASSIGN(TrayAudio);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_AUDIO_TRAY_AUDIO_H_