s/\bArc\b/ARC/g for ARC related code.

ash/common/system/chromeos/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_COMMON_SYSTEM_CHROMEOS_AUDIO_TRAY_AUDIO_H_
 #define ASH_COMMON_SYSTEM_CHROMEOS_AUDIO_TRAY_AUDIO_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 18 matching lines @@
 
 // The system tray item for audio input and output.
 class ASH_EXPORT TrayAudio : public TrayImageItem,
                              public chromeos::CrasAudioHandler::AudioObserver,
                              public display::DisplayObserver,
                              public chromeos::PowerManagerClient::Observer {
  public:
   explicit TrayAudio(SystemTray* system_tray);
   ~TrayAudio() override;
 
-  // Temporarily shows the pop-up volume slider on all displays. Used by ARC++
+  // Temporarily shows the pop-up volume slider on all displays. Used by ARC
   // when an Android app changes the system volume.
   static void ShowPopUpVolumeView();
 
   tray::VolumeView* volume_view_for_testing() { return volume_view_; }
   bool pop_up_volume_view_for_testing() { return pop_up_volume_view_; }
 
  private:
   // Overridden from display::DisplayObserver.
   void OnDisplayAdded(const display::Display& new_display) override;
   void OnDisplayRemoved(const display::Display& old_display) override;
@@ skipping 35 matching lines @@
   bool pop_up_volume_view_;
 
   tray::AudioDetailedView* audio_detail_view_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayAudio);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_CHROMEOS_AUDIO_TRAY_AUDIO_H_