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

ui/message_center/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_MESSAGE_VIEW_H_
 #define UI_MESSAGE_CENTER_MESSAGE_VIEW_H_
 
 #include "ui/message_center/notification_list.h"
 #include "ui/views/controls/button/button.h"
 #include "ui/views/controls/slide_out_view.h"
@@ skipping 25 matching lines @@
   // Creates the elements that make up the view layout. Must be called
   // immediately after construction.
   virtual void SetUpView() = 0;
 
   void set_scroller(views::ScrollView* scroller) { scroller_ = scroller; }
 
   // views::View overrides.
   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
 
   // ui::EventHandler overrides.
-  virtual ui::EventResult OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
+  virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // Overridden from ButtonListener.
   virtual void ButtonPressed(views::Button* sender,
                              const ui::Event& event) OVERRIDE;
 
  protected:
   MessageView();
 
   // Shows the menu for the notification.
   void ShowMenu(gfx::Point screen_location);
 
   // Overridden from views::SlideOutView.
   virtual void OnSlideOut() OVERRIDE;
 
   NotificationList::Delegate* list_delegate_;
   NotificationList::Notification notification_;
   views::ImageButton* close_button_;
 
   views::ScrollView* scroller_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageView);
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_MESSAGE_VIEW_H_