Remove ash_shell audio system tray item on Windows.

ash/system/win/audio/tray_audio_delegate_win.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_WIN_AUDIO_TRAY_AUDIO_DELEGATE_WIN_H_
-#define ASH_SYSTEM_WIN_AUDIO_TRAY_AUDIO_DELEGATE_WIN_H_
-
-#include <audioclient.h>
-#include <mmdeviceapi.h>
-
-#include "ash/ash_export.h"
-#include "ash/system/audio/tray_audio_delegate.h"
-#include "base/compiler_specific.h"
-#include "base/win/scoped_comptr.h"
-
-namespace ash {
-namespace system {
-
-class ASH_EXPORT TrayAudioDelegateWin : public TrayAudioDelegate {
- public:
-  ~TrayAudioDelegateWin() override {}
-
-  // Overridden from TrayAudioDelegate.
-  void AdjustOutputVolumeToAudibleLevel() override;
-  int GetOutputDefaultVolumeMuteLevel() override;
-  int GetOutputVolumeLevel() override;
-  int GetActiveOutputDeviceIconId() 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;
-
- private:
-  base::win::ScopedComPtr<ISimpleAudioVolume> CreateDefaultVolumeControl();
-};
-
-}  // namespace system
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_WIN_AUDIO_TRAY_AUDIO_DELEGATE_WIN_H_