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..73426687593c018ad259bd4f4950ba7c6e2259f3 100644
--- a/chromeos/audio/cras_audio_handler.h
+++ b/chromeos/audio/cras_audio_handler.h
@@ -155,10 +155,15 @@ 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);
+
   // Sets all active input devices' gain level to |gain_percent|, whose range is
   // from 0-100%.
   virtual void SetInputGainPercent(int gain_percent);
@@ -432,11 +437,20 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
 
   bool cras_service_available_ = false;
 
-  bool initializing_audio_state_ = false;
+  // A mask with non-zero value indicates it is an automated volume changed.
+  // It can be set on AutomatedVolumeChangeReason bits.
+  // VOLUME_CHANGE_INITIALIZING_AUDIO_STATE indicates it is from intializaing
+  // audio state.
+  // VOLUME_CHANGE_MAXIMIZE_MODE_SCREENSHOT indicates it is from restoring
+  // volume in maximimize mode screenshot.
+  int automated_volume_change_ = 0;
+
   int init_volume_;
   uint64_t init_node_id_;
   int init_volume_count_ = 0;
 
+  int maximize_mode_screenshot_count_ = 0;

[Daniel Erat, 2016/07/29 22:27:30]

keeping a bitmap and a counter in parallel seems a bit strange. i'm wondering if
it'd be more appropriate to have e.g. a std::deque<AutomatedVolumeChangeReason>.
assuming you get replies from cras in the same order as requests to it, could
you just pop the reasons off the front of it in-order?

[Qiang(Joe) Xu, 2016/08/01 20:28:09]

done. thanks!

+
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);