ui: Cleanup class/struct forward declarations

ui/views/widget/desktop_aura/x11_move_loop_delegate.h

 // Copyright 2014 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_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_DELEGATE_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_DELEGATE_H_
 
+namespace gfx {
+class Point;
+}
+
 namespace views {
 
 // Receives mouse events while the X11MoveLoop is tracking a drag.
 class X11MoveLoopDelegate {
  public:
   // Called when we receive a mouse move event.
   virtual void OnMouseMovement(const gfx::Point& screen_point,
                                int flags,
                                base::TimeTicks event_time) = 0;
 
   // Called when the mouse button is released.
   virtual void OnMouseReleased() = 0;
 
   // Called when the user has released the mouse button. The move loop will
   // release the grab after this has been called.
   virtual void OnMoveLoopEnded() = 0;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_DELEGATE_H_