Fix the UI issue for showing output muted in ash tray after the device wakes up with hdmi output re…

chromeos/audio/cras_audio_handler.h

 // Copyright (c) 2013 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 CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
 #define CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
 
 #include <stdint.h>
 #include <queue>
 
@@ skipping 23 matching lines @@
                               std::vector<AudioDevice>,
                               AudioDeviceCompare> AudioDevicePriorityQueue;
   typedef std::vector<uint64_t> NodeIdList;
 
   class AudioObserver {
    public:
     // Called when an active output volume changed.
     virtual void OnOutputNodeVolumeChanged(uint64_t node_id, int volume);
 
     // Called when output mute state changed.
-    virtual void OnOutputMuteChanged(bool mute_on);
+    // |mute_on|: True if output is muted.
+    // |system_adjust|: True if the mute state is adjusted by the system
+    // automatically(i.e. not by user). UI should reflect the system's mute
+    // state, but it should not be too loud, e.g., the volume pop up window
+    // should not be triggered.
+    virtual void OnOutputMuteChanged(bool mute_on, bool system_adjust);
 
     // Called when active input node's gain changed.
     virtual void OnInputNodeGainChanged(uint64_t node_id, int gain);
 
     // Called when input mute state changed.
     virtual void OnInputMuteChanged(bool mute_on);
 
     // Called when audio nodes changed.
     virtual void OnAudioNodesChanged();
 
@@ skipping 299 matching lines @@
   bool hdmi_rediscovering_;
 
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_