events: Move some files into ui/base/events/

ash/drag_drop/drag_drop_tracker.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_DRAG_DROP_DRAG_DROP_TRACKER_H_
 #define ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
-#include "ui/base/event.h"
+#include "ui/base/events/event.h"
 
 namespace aura {
 class RootWindow;
 class Window;
 }
 
 namespace ash {
 namespace internal {
 
 // Provides functions for handling drag events inside and outside the root
@@ skipping 20 matching lines @@
   // A window for capturing drag events while dragging.
   scoped_ptr<aura::Window> capture_window_;
 
   DISALLOW_COPY_AND_ASSIGN(DragDropTracker);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_