Get rid of the EnableClose() infrastructure in Widget.

ui/aura_shell/toplevel_frame_view.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 UI_AURA_SHELL_TOPLEVEL_FRAME_VIEW_H_
 #define UI_AURA_SHELL_TOPLEVEL_FRAME_VIEW_H_
 #pragma once
 
 #include "ui/aura_shell/aura_shell_export.h"
 #include "ui/views/window/non_client_view.h"
@@ skipping 38 matching lines @@
   gfx::Rect GetHiddenBoundsForSizingBorder(int frame_component) const;
   gfx::Rect GetVisibleBoundsForSizingBorder(int frame_component) const;
 
   // Overridden from views::NonClientFrameView:
   virtual gfx::Rect GetBoundsForClientView() const OVERRIDE;
   virtual gfx::Rect GetWindowBoundsForClientBounds(
       const gfx::Rect& client_bounds) const OVERRIDE;
   virtual int NonClientHitTest(const gfx::Point& point) OVERRIDE;
   virtual void GetWindowMask(const gfx::Size& size,
                              gfx::Path* window_mask) OVERRIDE;
-  virtual void EnableClose(bool enable) OVERRIDE;
   virtual void ResetWindowControls() OVERRIDE;
   virtual void UpdateWindowIcon() OVERRIDE;
 
   // Overridden from views::View:
   virtual void Layout() OVERRIDE;
   virtual void OnMouseMoved(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseExited(const views::MouseEvent& event) OVERRIDE;
   virtual views::View* GetEventHandlerForPoint(
       const gfx::Point& point) OVERRIDE;
   virtual gfx::NativeCursor GetCursor(const views::MouseEvent& event) OVERRIDE;
 
   gfx::Rect client_view_bounds_;
 
   int current_hittest_code_;
 
   WindowCaption* caption_;
   SizingBorder* left_edge_;
   SizingBorder* right_edge_;
   SizingBorder* bottom_edge_;
 
   DISALLOW_COPY_AND_ASSIGN(ToplevelFrameView);
 };
 
 }  // namespace internal
 }  // namespace aura_shell
 
 #endif  // #ifndef UI_AURA_SHELL_TOPLEVEL_FRAME_VIEW_H_