Get rid of the EnableClose() infrastructure in Widget.

ui/views/widget/native_widget_aura.cc

 // 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.
 
 #include "ui/views/widget/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/string_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/drag_drop_client.h"
@@ skipping 372 matching lines @@
         FROM_HERE,
         base::Bind(&NativeWidgetAura::CloseNow,
                    close_widget_factory_.GetWeakPtr()));
   }
 }
 
 void NativeWidgetAura::CloseNow() {
   delete window_;
 }
 
-void NativeWidgetAura::EnableClose(bool enable) {
-  // http://crbug.com/102581
-  NOTIMPLEMENTED();
-}
-
 void NativeWidgetAura::Show() {
   ShowWithWindowState(ui::SHOW_STATE_INACTIVE);
 }
 
 void NativeWidgetAura::Hide() {
   window_->Hide();
 }
 
 void NativeWidgetAura::ShowMaximizedWithBounds(
     const gfx::Rect& restored_bounds) {
@@ skipping 383 matching lines @@
   NOTIMPLEMENTED();
 }
 
 // static
 bool NativeWidgetPrivate::IsMouseButtonDown() {
   return aura::Desktop::GetInstance()->IsMouseButtonDown();
 }
 
 }  // namespace internal
 }  // namespace views