Fix Volume slider is captured in screenshot done in touchview mode

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 <stddef.h>
 #include <stdint.h>
 #include <queue>
@@ skipping 137 matching lines @@
   // This call can be invoked from I/O thread or UI thread because
   // it does not need to access CrasAudioClient on DBus.
   virtual void GetAudioDevices(AudioDeviceList* device_list) const;
 
   virtual bool GetPrimaryActiveOutputDevice(AudioDevice* device) const;
 
   // Whether there is alternative input/output audio device.
   virtual bool has_alternative_input() const;
   virtual bool has_alternative_output() const;
 
-  // Sets all active output devices' volume level to |volume_percent|, whose
+  // Sets all active output devices' volume levels to |volume_percent|, whose
   // range is from 0-100%.
   virtual void SetOutputVolumePercent(int volume_percent);
 
+  // Sets all active output devices' volume levels to |volume_percent|, whose
+  // range is from 0-100%, without notifying observers.
+  virtual void SetOutputVolumePercentWithoutNotifyingObservers(
+      int volume_percent);
+
   // Sets all active input devices' gain level to |gain_percent|, whose range is
   // from 0-100%.
   virtual void SetInputGainPercent(int gain_percent);
 
   // Adjusts all active output devices' volume up (positive percentage) or down
   // (negative percentage).
   virtual void AdjustOutputVolumeByPercent(int adjust_by_percent);
 
   // Adjusts all active output devices' volume to a minimum audible level if it
   // is too low.
@@ skipping 253 matching lines @@
   // Failures are not logged at startup, since CRAS may not be running yet.
   bool log_errors_;
 
   // Timer for HDMI re-discovering grace period.
   base::OneShotTimer hdmi_rediscover_timer_;
   int hdmi_rediscover_grace_period_duration_in_ms_;
   bool hdmi_rediscovering_;
 
   bool cras_service_available_ = false;
 
-  bool initializing_audio_state_ = false;
+  // A mask with non-zero value indicates it is an automated volume changed.

[Daniel Erat, 2016/07/29 17:53:38]

please document the name of the enum that is used in this bitmap

[Qiang(Joe) Xu, 2016/07/29 18:58:23]

Done.

+  int automated_volume_change_ = 0;
+
   int init_volume_;
   uint64_t init_node_id_;
   int init_volume_count_ = 0;
 
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_