[Notifications] Fix swipe to close for ARC notifications.

ui/message_center/views/message_view.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 "ui/message_center/views/message_view.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/simple_menu_model.h"
@@ skipping 188 matching lines @@
       SetDrawBackgroundAsActive(false);
       controller_->ClickOnNotification(notification_id_);
       event->SetHandled();
       return;
     }
     default: {
       // Do nothing
     }
   }
 
+  slide_out_controller_.OnGestureEvent(event);
+  // Do not return here by checking handled(). SlideOutController calls
+  // SetHandled() even though the scroll gesture doesn't make no (or little)
+  // effects on the slide-out behavior. See http://crbug.com/172991
+
   if (!event->IsScrollGestureEvent() && !event->IsFlingScrollEvent())
     return;
 
   if (scroller_)
     scroller_->OnGestureEvent(event);
   event->SetHandled();
 }
 
 ui::Layer* MessageView::GetSlideOutLayer() {
   return is_nested_ ? layer() : GetWidget()->GetLayer();
 }
 
 void MessageView::OnSlideOut() {
   controller_->RemoveNotification(notification_id_, true);  // By user.
 }
 
 void MessageView::OnCloseButtonPressed() {
   controller_->RemoveNotification(notification_id_, true);  // By user.
 }
 
 void MessageView::SetDrawBackgroundAsActive(bool active) {
   background_view_->background()->
       SetNativeControlColor(active ? kHoveredButtonBackgroundColor :
                                      kNotificationBackgroundColor);
   SchedulePaint();
 }
 
 }  // namespace message_center