Fix Volume slider is captured in screenshot done in touchview mode

ash/common/system/tray/system_tray.h

 // Copyright (c) 2012 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_TRAY_SYSTEM_TRAY_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_H_
 
 #include <map>
 #include <memory>
 #include <vector>
@@ skipping 56 matching lines @@
   // non-zero, then the view is automatically closed after the specified time.
   void ShowDetailedView(SystemTrayItem* item,
                         int close_delay_in_seconds,
                         bool activate,
                         BubbleCreationType creation_type);
 
   // Continue showing the existing detailed view, if any, for |close_delay|
   // seconds.
   void SetDetailedViewCloseDelay(int close_delay);
 
-  // Hides the detailed view for |item|.
-  void HideDetailedView(SystemTrayItem* item);
+  // Hides the detailed view for |item|. If |hide_animation| is false, disable
+  // the hiding animation for hiding |item|.
+  void HideDetailedView(SystemTrayItem* item, bool hide_animation);

[Daniel Erat, 2016/07/28 22:20:40]

|hide_animation| is a confusing name, since it could also be interpreted as
"hide the animation", i.e. pass true to not display the animation. please rename
it to something like |animate|.

[Qiang(Joe) Xu, 2016/07/28 23:15:57]

Done.

 
   // Shows the notification view for |item|.
   void ShowNotificationView(SystemTrayItem* item);
 
   // Hides the notification view for |item|.
   void HideNotificationView(SystemTrayItem* item);
 
   // Updates the items when the login status of the system changes.
   void UpdateAfterLoginStatusChange(LoginStatus login_status);
 
@@ skipping 166 matching lines @@
   // A reference to the Screen share and capture item.
   ScreenTrayItem* screen_capture_tray_item_;  // not owned
   ScreenTrayItem* screen_share_tray_item_;    // not owned
 
   DISALLOW_COPY_AND_ASSIGN(SystemTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_H_