Re-land:

views/widget/native_widget_delegate.h

 // Copyright (c) 2011 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 VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 #define VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 #pragma once
 
 namespace gfx {
 class Canvas;
@@ skipping 32 matching lines @@
       const gfx::Rect& dirty_region) = 0;
 
   // Paints the rootview in the canvas. This will also refresh the compositor
   // tree if necessary when accelerated painting is enabled.
   virtual void OnNativeWidgetPaint(gfx::Canvas* canvas) = 0;
 
   // Mouse and key event handlers.
   virtual bool OnKeyEvent(const KeyEvent& event) = 0;
   virtual bool OnMouseEvent(const MouseEvent& event) = 0;
   virtual void OnMouseCaptureLost() = 0;
+
+  //
+  virtual Widget* AsWidget() = 0;
+  virtual const Widget* AsWidget() const = 0;
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_