events: Change gesture-event handler in EventHandler to not return any values.

ash/system/tray/tray_notification_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 ASH_SYSTEM_TRAY_TRAY_NOTIFICATION_VIEW_H_
 #define ASH_SYSTEM_TRAY_TRAY_NOTIFICATION_VIEWS_H_
 
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/controls/slide_out_view.h"
 
@@ skipping 41 matching lines @@
                           const gfx::ImageSkia& image);
 
   // Overridden from ButtonListener.
   virtual void ButtonPressed(views::Button* sender,
                              const ui::Event& event) OVERRIDE;
 
   // Overridden from views::View.
   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
 
   // Overridden from ui::EventHandler.
-  virtual ui::EventResult OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
+  virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
  protected:
   // Called when the close button is pressed. Does nothing by default.
   virtual void OnClose();
   // Called when the notification is clicked on. Does nothing by default.
   virtual void OnClickAction();
 
   // Overridden from views::SlideOutView.
   virtual void OnSlideOut() OVERRIDE;
 
   SystemTrayItem* owner() { return owner_; }
 
  private:
   void HandleClose();
   void HandleClickAction();
 
   SystemTrayItem* owner_;
   int icon_id_;
   views::ImageView* icon_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayNotificationView);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_TRAY_NOTIFICATION_VIEWS_H_