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

ui/views/view_constants_aura.h

+// Copyright (c) 2013 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_VIEW_CONSTANTS_AURA_H_
+#define UI_VIEWS_VIEW_CONSTANTS_AURA_H_
+
+#include "ui/aura/window.h"
+#include "ui/views/views_export.h"
+
+namespace views {
+class View;
+
+// A property key to indicate the view the window is associated with. If
+// specified, the z-order of the view, relative to other views, dictates the
+// z-order of the window and its associated layer. The associated view must
+// have the same parent widget as the window on which the property is set.
+VIEWS_EXPORT extern const aura::WindowProperty<View*>* const kHostViewKey;
+
+}  // namespace views
+
+#endif  // UI_VIEWS_VIEW_CONSTANTS_AURA_H_