ui: Cleanup class/struct forward declarations

ui/views/widget/native_widget_delegate.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_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 #define UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 
 #include <vector>
 
 #include "ui/events/event_constants.h"
 #include "ui/views/views_export.h"
 
 namespace gfx {
-class Canvas;
 class Path;
 class Point;
 class Size;
 }
 
 namespace ui {
 class GestureEvent;
 class KeyEvent;
 class Layer;
 class MouseEvent;
 class PaintContext;
 class ScrollEvent;
-class TouchEvent;
 }
 
 namespace views {
 class Widget;
 
 namespace internal {
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeWidgetDelegate
 //
@@ skipping 110 matching lines @@
   // later.  Returns true if the initial focus has been set or the window should
   // not set the initial focus, or false if the caller should set the initial
   // focus (if any).
   virtual bool SetInitialFocus(ui::WindowShowState show_state) = 0;
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_