Makes WmWindowMus restore bounds use property

ash/mus/bridge/wm_window_mus.h

 // Copyright 2016 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_MUS_BRIDGE_WM_WINDOW_MUS_H_
 #define ASH_MUS_BRIDGE_WM_WINDOW_MUS_H_
 
 #include <memory>
 
 #include "ash/common/shell_window_ids.h"
@@ skipping 267 matching lines @@
   std::unique_ptr<wm::WindowState> window_state_;
 
   views::Widget* widget_ = nullptr;
 
   WidgetCreationType widget_creation_type_ = WidgetCreationType::INTERNAL;
 
   base::ObserverList<WmWindowObserver> observers_;
 
   std::unique_ptr<MusLayoutManagerAdapter> layout_manager_adapter_;
 
-  std::unique_ptr<gfx::Rect> restore_bounds_in_screen_;
-
   ui::WindowShowState restore_show_state_ = ui::SHOW_STATE_DEFAULT;
 
   bool snap_children_to_pixel_boundary_ = false;
 
   // If true child windows should get a slightly larger hit region to make
   // resizing easier.
   bool children_use_extended_hit_region_ = false;
 
   base::ObserverList<WmTransientWindowObserver, true> transient_observers_;
 
   // If true the minimum size is 0x0, default is minimum size comes from widget.
   bool use_empty_minimum_size_for_testing_ = false;
 
   ui::wm::WindowType wm_window_type_ = ui::wm::WINDOW_TYPE_UNKNOWN;
   // Set to true if set_window_type() is called.
   bool is_wm_window_type_set_ = false;
 
   BoundsInScreenBehavior child_bounds_in_screen_behavior_ =
       BoundsInScreenBehavior::USE_LOCAL_COORDINATES;
 
   bool locked_to_root_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(WmWindowMus);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_BRIDGE_WM_WINDOW_MUS_H_