events: Move EventTarget into Event.

ui/base/events/event_handler.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_BASE_EVENTS_EVENT_CONSTANTS_EVENTS_EVENT_HANDLER_H_
 #define UI_BASE_EVENTS_EVENT_CONSTANTS_EVENTS_EVENT_HANDLER_H_
 
 #include <vector>
 
 #include "ui/base/events/event_constants.h"
 #include "ui/base/ui_export.h"
 
 namespace ui {
 
 class GestureEvent;
 class KeyEvent;
 class MouseEvent;
 class ScrollEvent;
 class TouchEvent;
 
 class EventTarget;
 
 // Dispatches events to appropriate targets.
 class UI_EXPORT EventHandler {
  public:
   EventHandler() {}
   virtual ~EventHandler() {}
 
-  virtual EventResult OnKeyEvent(EventTarget* target,
-                                 KeyEvent* event) = 0;
+  virtual EventResult OnKeyEvent(KeyEvent* event) = 0;
 
-  virtual EventResult OnMouseEvent(EventTarget* target,
-                                   MouseEvent* event) = 0;
+  virtual EventResult OnMouseEvent(MouseEvent* event) = 0;
 
-  virtual EventResult OnScrollEvent(EventTarget* target,
-                                    ScrollEvent* event) = 0;
+  virtual EventResult OnScrollEvent(ScrollEvent* event) = 0;
 
-  virtual TouchStatus OnTouchEvent(EventTarget* target,
-                                   TouchEvent* event) = 0;
+  virtual TouchStatus OnTouchEvent(TouchEvent* event) = 0;
 
-  virtual EventResult OnGestureEvent(EventTarget* target,
-                                     GestureEvent* event) = 0;
+  virtual EventResult OnGestureEvent(GestureEvent* event) = 0;
 };
 
 typedef std::vector<EventHandler*> EventHandlerList;
 
 }  // namespace ui
 
 #endif  // UI_BASE_EVENTS_EVENT_CONSTANTS_EVENTS_EVENT_HANDLER_H_