ui: Cleanup class/struct forward declarations

ui/events/event_dispatcher.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_EVENTS_EVENT_DISPATCHER_H_
 #define UI_EVENTS_EVENT_DISPATCHER_H_
 
 #include "base/auto_reset.h"
 #include "base/macros.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/event_handler.h"
 #include "ui/events/events_export.h"
 
 namespace ui {
 
 class EventDispatcher;
 class EventTarget;
-class EventTargeter;
 
 struct EventDispatchDetails {
   EventDispatchDetails()
       : dispatcher_destroyed(false),
         target_destroyed(false) {}
   bool dispatcher_destroyed;
   bool target_destroyed;
 };
 
 class EVENTS_EXPORT EventDispatcherDelegate {
@@ skipping 69 matching lines @@
   Event* current_event_;
 
   EventHandlerList handler_list_;
 
   DISALLOW_COPY_AND_ASSIGN(EventDispatcher);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_DISPATCHER_H_