[Notifications] Fix swipe to close for ARC notifications.

ui/message_center/views/message_view.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 UI_MESSAGE_CENTER_VIEWS_MESSAGE_VIEW_H_
 #define UI_MESSAGE_CENTER_VIEWS_MESSAGE_VIEW_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 54 matching lines @@
   bool OnKeyPressed(const ui::KeyEvent& event) override;
   bool OnKeyReleased(const ui::KeyEvent& event) override;
   void OnPaint(gfx::Canvas* canvas) override;
   void OnFocus() override;
   void OnBlur() override;
   void Layout() override;
   void OnGestureEvent(ui::GestureEvent* event) override;
 
   // views::SlideOutController::Delegate
   ui::Layer* GetSlideOutLayer() override;
+  void OnSlideChanged() override;
   void OnSlideOut() override;
 
   void set_scroller(views::ScrollView* scroller) { scroller_ = scroller; }
   std::string notification_id() { return notification_id_; }
   NotifierId notifier_id() { return notifier_id_; }
   const base::string16& display_source() const { return display_source_; }
   bool pinned() const { return pinned_; }
 
   void set_controller(MessageCenterController* controller) {
     controller_ = controller;
@@ skipping 32 matching lines @@
   // True if |this| is embedded in another view. Equivalent to |!top_level| in
   // MessageViewFactory parlance.
   bool is_nested_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(MessageView);
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_VIEWS_MESSAGE_VIEW_H_