Revert "chromeos: Move files in //ash/common to //ash, part 1"

ash/system/audio/tray_audio_delegate_chromeos.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_DELEGATE_CHROMEOS_H_
-#define ASH_SYSTEM_AUDIO_TRAY_AUDIO_DELEGATE_CHROMEOS_H_
-
-#include "ash/ash_export.h"
-#include "ash/system/audio/tray_audio_delegate.h"
-
-namespace ash {
-namespace system {
-
-class ASH_EXPORT TrayAudioDelegateChromeOs : public TrayAudioDelegate {
- public:
-  ~TrayAudioDelegateChromeOs() override {}
-
-  // Overridden from TrayAudioDelegate.
-  void AdjustOutputVolumeToAudibleLevel() override;
-  int GetOutputDefaultVolumeMuteLevel() override;
-  int GetOutputVolumeLevel() override;
-  const gfx::VectorIcon& GetActiveOutputDeviceVectorIcon() override;
-  bool HasAlternativeSources() override;
-  bool IsOutputAudioMuted() override;
-  void SetOutputAudioIsMuted(bool is_muted) override;
-  void SetOutputVolumeLevel(int level) override;
-  void SetInternalSpeakerChannelMode(AudioChannelMode mode) override;
-  void SetActiveHDMIOutoutRediscoveringIfNecessary(
-      bool force_rediscovering) override;
-};
-
-}  // namespace system
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_AUDIO_TRAY_AUDIO_DELEGATE_CHROMEOS_H_