Unify window fullscreen and minimizing implementation

ui/views/mus/desktop_window_tree_host_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 UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_MUS_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_MUS_H_
 
 #include <memory>
 #include <set>
 
@@ skipping 125 matching lines @@
 
   // aura::EnvObserver:
   void OnWindowInitialized(aura::Window* window) override;
   void OnActiveFocusClientChanged(aura::client::FocusClient* focus_client,
                                   aura::Window* window) override;
 
   internal::NativeWidgetDelegate* native_widget_delegate_;
 
   DesktopNativeWidgetAura* desktop_native_widget_aura_;
 
-  // State to restore window to when exiting fullscreen. Only valid if
-  // fullscreen.
-  ui::WindowShowState fullscreen_restore_state_;
-
   // We can optionally have a parent which can order us to close, or own
   // children who we're responsible for closing when we CloseNow().
   DesktopWindowTreeHostMus* parent_ = nullptr;
   std::set<DesktopWindowTreeHostMus*> children_;
 
   bool is_active_ = false;
 
   std::unique_ptr<wm::CursorManager> cursor_manager_;
 
   bool auto_update_client_area_ = true;
 
   // Used so that Close() isn't immediate.
   base::WeakPtrFactory<DesktopWindowTreeHostMus> close_widget_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopWindowTreeHostMus);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_MUS_H_