Use template specialization to generate WindowProperty code

ui/aura/client/aura_constants.cc

 // 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.
 
 #include "ui/aura/client/aura_constants.h"
 
 #include "ui/aura/window_property.h"
 #include "ui/gfx/rect.h"
 
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, bool)
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, ui::ModalType)
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, gfx::Rect*)
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, ui::InputMethod*)
 DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, ui::WindowShowState)
+DECLARE_EXPORTED_WINDOW_PROPERTY_TYPE(AURA_EXPORT, void*)
 
 namespace aura {
 namespace client {
 
 // Alphabetical sort.
 
 DEFINE_WINDOW_PROPERTY_KEY(bool, kAlwaysOnTopKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kAnimationsDisabledKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kCanMaximizeKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kCanMinimizeKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kCanResizeKey, true);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kConstrainedWindowKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kDrawAttentionKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(Window*, kHostWindowKey, NULL);
 DEFINE_WINDOW_PROPERTY_KEY(ui::ModalType, kModalKey, ui::MODAL_TYPE_NONE);
 // gfx::Rect object for RestoreBoundsKey property is owned by the window
 // and will be freed automatically.
 DEFINE_OWNED_WINDOW_PROPERTY_KEY(gfx::Rect, kRestoreBoundsKey, NULL);
 DEFINE_WINDOW_PROPERTY_KEY(
     ui::WindowShowState, kRestoreShowStateKey, ui::SHOW_STATE_DEFAULT);
 DEFINE_WINDOW_PROPERTY_KEY(ui::InputMethod*, kRootWindowInputMethodKey, NULL);
 DEFINE_WINDOW_PROPERTY_KEY(
     ui::WindowShowState, kShowStateKey, ui::SHOW_STATE_DEFAULT);
 
 }  // namespace client
 }  // namespace aura