WidgetDelegateView is its own contents view.

ash/shell/toplevel_window.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_SHELL_TOPLEVEL_WINDOW_H_
 #define ASH_SHELL_TOPLEVEL_WINDOW_H_
 
 #include "base/macros.h"
 #include "ui/views/widget/widget_delegate.h"
 
@@ skipping 22 matching lines @@
   // Overridden from views::View:
   void OnPaint(gfx::Canvas* canvas) override;
 
   // Overridden from views::WidgetDelegate:
   base::string16 GetWindowTitle() const override;
   void SaveWindowPlacement(const gfx::Rect& bounds,
                            ui::WindowShowState show_state) override;
   bool GetSavedWindowPlacement(const views::Widget* widget,
                                gfx::Rect* bounds,
                                ui::WindowShowState* show_state) const override;
-  View* GetContentsView() override;
   bool CanResize() const override;
   bool CanMaximize() const override;
   bool CanMinimize() const override;
 
   const CreateParams params_;
 
   DISALLOW_COPY_AND_ASSIGN(ToplevelWindow);
 };
 
 }  // namespace shell
 }  // namespace ash
 
 #endif  // ASH_SHELL_TOPLEVEL_WINDOW_H_