Fix Volume slider is captured in screenshot done in touchview mode

ash/common/system/tray/system_tray.cc

 // 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.
 
 #include "ash/common/system/tray/system_tray.h"
 
 #include "ash/common/ash_switches.h"
 #include "ash/common/login_status.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/wm_shelf.h"
@@ skipping 24 matching lines @@
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/events/event_constants.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/common/system/chromeos/audio/tray_audio_chromeos.h"
 #include "ash/common/system/chromeos/bluetooth/tray_bluetooth.h"
 #include "ash/common/system/chromeos/brightness/tray_brightness.h"
 #include "ash/common/system/chromeos/enterprise/tray_enterprise.h"
 #include "ash/common/system/chromeos/media_security/multi_profile_media_tray_item.h"
 #include "ash/common/system/chromeos/network/tray_network.h"
 #include "ash/common/system/chromeos/network/tray_sms.h"
 #include "ash/common/system/chromeos/network/tray_vpn.h"
@@ skipping 215 matching lines @@
             persistent);
   if (system_bubble_)
     system_bubble_->bubble()->StartAutoCloseTimer(close_delay);
 }
 
 void SystemTray::SetDetailedViewCloseDelay(int close_delay) {
   if (HasSystemBubbleType(SystemTrayBubble::BUBBLE_TYPE_DETAILED))
     system_bubble_->bubble()->StartAutoCloseTimer(close_delay);
 }
 
-void SystemTray::HideDetailedView(SystemTrayItem* item) {
+void SystemTray::HideDetailedView(SystemTrayItem* item, bool hide_animation) {
+  if (!hide_animation) {
+    // In unittest, GetSystemBubble might return nullptr.
+    if (GetSystemBubble()) {
+      GetSystemBubble()
+          ->bubble_view()
+          ->GetWidget()
+          ->SetVisibilityAnimationTransition(

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

does this affect future transitions, or does a new view get created each time
the bubble is shown?

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

Yes, systembubble is autoclosed everytime. So this should be fine. 

+              views::Widget::VisibilityTransition::ANIMATE_NONE);
+    }
+  }
   if (item != detailed_item_)
     return;
   DestroySystemBubble();
   UpdateNotificationBubble();
 }
 
 void SystemTray::ShowNotificationView(SystemTrayItem* item) {
   if (std::find(notification_items_.begin(), notification_items_.end(), item) !=
       notification_items_.end())
     return;
@@ skipping 478 matching lines @@
           .work_area()
           .height();
   if (work_area_height > 0) {
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Ash.SystemMenu.PercentageOfWorkAreaHeightCoveredByMenu",
         100 * bubble_view->height() / work_area_height, 1, 300, 100);
   }
 }
 
 }  // namespace ash