chromeos: Make system tray audio item observe CrasAudioHandler directly

ash/common/system/tray/system_tray_notifier.h

 // Copyright 2016 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_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_NOTIFIER_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_NOTIFIER_H_
 
 #include <string>
 
 #include "ash/ash_export.h"
 #include "ash/common/accessibility_types.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 
 #if defined(OS_CHROMEOS)
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #endif
 
 namespace ash {
 
 class AccessibilityObserver;
 class ClockObserver;
 class IMEObserver;
 struct UpdateInfo;
 class UpdateObserver;
 class UserObserver;
 
 #if defined(OS_CHROMEOS)
-class AudioObserver;
 class BluetoothObserver;
 class EnterpriseDomainObserver;
 class LastWindowClosedObserver;
 class LogoutButtonObserver;
 class MediaCaptureObserver;
 class NetworkObserver;
 class NetworkPortalDetectorObserver;
 class ScreenCaptureObserver;
 class ScreenShareObserver;
 class SessionLengthLimitObserver;
@@ skipping 32 matching lines @@
   void RemoveUpdateObserver(UpdateObserver* observer);
   void NotifyUpdateRecommended(const UpdateInfo& info);
 
   // User.
   void AddUserObserver(UserObserver* observer);
   void RemoveUserObserver(UserObserver* observer);
   void NotifyUserUpdate();
   void NotifyUserAddedToSession();
 
 #if defined(OS_CHROMEOS)
-  // Audio.
-  void AddAudioObserver(AudioObserver* observer);
-  void RemoveAudioObserver(AudioObserver* observer);
-  void NotifyAudioOutputVolumeChanged(uint64_t node_id, double volume);
-  void NotifyAudioOutputMuteChanged(bool mute_on, bool system_adjust);
-  void NotifyAudioNodesChanged();
-  void NotifyAudioActiveOutputNodeChanged();
-  void NotifyAudioActiveInputNodeChanged();
-
   // Bluetooth.
   void AddBluetoothObserver(BluetoothObserver* observer);
   void RemoveBluetoothObserver(BluetoothObserver* observer);
   void NotifyRefreshBluetooth();
   void NotifyBluetoothDiscoveringChanged();
 
   // Enterprise domain.
   void AddEnterpriseDomainObserver(EnterpriseDomainObserver* observer);
   void RemoveEnterpriseDomainObserver(EnterpriseDomainObserver* observer);
   void NotifyEnterpriseDomainChanged();
@@ skipping 58 matching lines @@
 #endif
 
  private:
   base::ObserverList<AccessibilityObserver> accessibility_observers_;
   base::ObserverList<ClockObserver> clock_observers_;
   base::ObserverList<IMEObserver> ime_observers_;
   base::ObserverList<UpdateObserver> update_observers_;
   base::ObserverList<UserObserver> user_observers_;
 
 #if defined(OS_CHROMEOS)
-  base::ObserverList<AudioObserver> audio_observers_;
   base::ObserverList<BluetoothObserver> bluetooth_observers_;
   base::ObserverList<EnterpriseDomainObserver> enterprise_domain_observers_;
   base::ObserverList<LastWindowClosedObserver> last_window_closed_observers_;
   base::ObserverList<LogoutButtonObserver> logout_button_observers_;
   base::ObserverList<MediaCaptureObserver> media_capture_observers_;
   base::ObserverList<NetworkObserver> network_observers_;
   base::ObserverList<NetworkPortalDetectorObserver>
       network_portal_detector_observers_;
   base::ObserverList<ScreenCaptureObserver> screen_capture_observers_;
   base::ObserverList<ScreenShareObserver> screen_share_observers_;
   base::ObserverList<SessionLengthLimitObserver>
       session_length_limit_observers_;
   base::ObserverList<TracingObserver> tracing_observers_;
   base::ObserverList<VirtualKeyboardObserver> virtual_keyboard_observers_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(SystemTrayNotifier);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_NOTIFIER_H_