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

ui/views/widget/native_widget_aura.h

Index: ui/views/widget/native_widget_aura.h
diff --git a/ui/views/widget/native_widget_aura.h b/ui/views/widget/native_widget_aura.h
index 3dc64d6159882297572c83ce438712a639c21e0f..080a5bc7f42bcdb21ed25f08fce5b67d5c672405 100644
--- a/ui/views/widget/native_widget_aura.h
+++ b/ui/views/widget/native_widget_aura.h
@@ -28,6 +28,7 @@ namespace views {
 
 class DropHelper;
 class NativeWidgetAuraWindowObserver;
+class NativeWidgetWindowReordererAura;
 class TooltipManagerAura;
 
 class VIEWS_EXPORT NativeWidgetAura
@@ -58,6 +59,7 @@ class VIEWS_EXPORT NativeWidgetAura
   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;
@@ -205,6 +207,10 @@ class VIEWS_EXPORT NativeWidgetAura
 
   scoped_ptr<TooltipManagerAura> tooltip_manager_;
 
+  // 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<NativeWidgetWindowReordererAura> window_reorderer_;
+
   scoped_ptr<NativeWidgetAuraWindowObserver> active_window_observer_;
 
   scoped_ptr<DropHelper> drop_helper_;