Eliminates all ash dependencies from WindowModalityController.

ash/wm/window_properties.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_WM_WINDOW_PROPERTIES_H_
 #define ASH_WM_WINDOW_PROPERTIES_H_
 
 #include "ash/ash_export.h"
 #include "ash/wm/property_util.h"
 #include "ui/aura/window.h"
@@ skipping 25 matching lines @@
 // Property set on all windows whose child windows' visibility changes are
 // animated.
 extern const aura::WindowProperty<bool>* const
     kChildWindowVisibilityChangesAnimatedKey;
 
 // True if the window is ignored by the shelf layout manager for purposes of
 // darkening the shelf.
 extern const aura::WindowProperty<bool>* const
     kIgnoredByShelfKey;
 
-// Transient child's modal parent.
-extern const aura::WindowProperty<aura::Window*>* const kModalParentKey;
-
 // Used to remember the show state before the window was minimized.
 extern const aura::WindowProperty<ui::WindowShowState>* const
     kRestoreShowStateKey;
 
 extern const aura::WindowProperty<RootWindowController*>* const
     kRootWindowControllerKey;
 
 // A property key to remember the frame painter for the solo-window in the root
 // window. It is only available for root windows.
 ASH_EXPORT extern const aura::WindowProperty<ash::FramePainter*>* const
@@ skipping 34 matching lines @@
 // True if the window is controlled by the workspace manager.
 extern const aura::WindowProperty<bool>* const
     kWindowTrackedByWorkspaceKey;
 
 // Alphabetical sort.
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_WINDOW_PROPERTIES_H_