Wires up transients for DesktopWindowTreeHostMus

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>
 
 #include "base/macros.h"
 #include "ui/aura/mus/window_tree_host_mus.h"
 #include "ui/views/mus/mus_export.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host.h"
 
 namespace views {
 
 class VIEWS_MUS_EXPORT DesktopWindowTreeHostMus
     : public DesktopWindowTreeHost,
@@ skipping 69 matching lines @@
   void SizeConstraintsChanged() 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_;
+
   // 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_