Reorder the NativeViews attached to a view via kViewHostKey according to the position of the view

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.h
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
index d46f0ba3ea76b15754602e62b08e2c13f222a718..fed511c26ae35fb2dbf064e2c58f968dedd646e5 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
@@ -37,6 +37,7 @@ class DesktopRootWindowHost;
 class DropHelper;
 class NativeWidgetAuraWindowObserver;
 class TooltipManagerAura;
+class WindowReorderer;
 
 class VIEWS_EXPORT DesktopNativeWidgetAura
     : public internal::NativeWidgetPrivate,
@@ -82,6 +83,7 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
   virtual const ui::Compositor* GetCompositor() const OVERRIDE;
   virtual ui::Compositor* GetCompositor() OVERRIDE;
   virtual ui::Layer* GetLayer() OVERRIDE;
+  virtual void ReorderNativeViews() OVERRIDE;
   virtual void ViewRemoved(View* view) OVERRIDE;
   virtual void SetNativeWindowProperty(const char* name, void* value) OVERRIDE;
   virtual void* GetNativeWindowProperty(const char* name) const OVERRIDE;
@@ -244,6 +246,10 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
 
   scoped_ptr<corewm::ShadowController> shadow_controller_;
 
+  // Reorders child windows of |window_| associated with a view based on the
+  // order of the associated views in the widget's view hierarchy.
+  scoped_ptr<WindowReorderer> window_reorderer_;
+
   DISALLOW_COPY_AND_ASSIGN(DesktopNativeWidgetAura);
 };