Fix Volume slider is captured in screenshot done in touchview mode

chromeos/audio/cras_audio_handler.h

Index: chromeos/audio/cras_audio_handler.h
diff --git a/chromeos/audio/cras_audio_handler.h b/chromeos/audio/cras_audio_handler.h
index c9110718e4a332a7bc0dde2b5a02d446857a8e2f..f78ff14cf4004a7ee1e34652e2a49dfe54292d05 100644
--- a/chromeos/audio/cras_audio_handler.h
+++ b/chromeos/audio/cras_audio_handler.h
@@ -38,6 +38,15 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
                               AudioDeviceCompare> AudioDevicePriorityQueue;
   typedef std::vector<uint64_t> NodeIdList;
 
+  // Volume change reasons that are not user-initiated.
+  enum AutomatedVolumeChangeReason {
+    // Indicates it is from intializaing audio state.
+    VOLUME_CHANGE_INITIALIZING_AUDIO_STATE,
+
+    // Indicates it is from restoring volume in maximimize mode screenshot.
+    VOLUME_CHANGE_MAXIMIZE_MODE_SCREENSHOT,
+  };
+
   class AudioObserver {
    public:
     // Called when an active output volume changed.
@@ -155,10 +164,16 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   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,
+      AutomatedVolumeChangeReason reason);
+
   // Sets all active input devices' gain level to |gain_percent|, whose range is
   // from 0-100%.
   virtual void SetInputGainPercent(int gain_percent);
@@ -432,10 +447,10 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
 
   bool cras_service_available_ = false;
 
-  bool initializing_audio_state_ = false;
+  std::deque<AutomatedVolumeChangeReason> automated_volume_change_reasons_;

[Daniel Erat, 2016/08/02 16:31:38]

i'd add a brief comment explaining how this is used. maybe something like:

  // FIFO list of reasons passed to
  // SetOutputVolumePercentWithoutNotifyingObservers() for which
  // we're still waiting for OutputNodeVolumeChanged() calls.
  // These are used to suppress notifications for those changes.

[Qiang(Joe) Xu, 2016/08/02 22:45:58]

done. That looks nice.

+
   int init_volume_;
   uint64_t init_node_id_;
-  int init_volume_count_ = 0;
 
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;