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

ui/views/view.h

 // Copyright (c) 2012 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_H_
 #define UI_VIEWS_VIEW_H_
 
 #include <algorithm>
 #include <map>
 #include <set>
@@ skipping 1086 matching lines @@
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE;
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual base::Closure PrepareForLayerBoundsChange() OVERRIDE;
 
   // Finds the layer that this view paints to (it may belong to an ancestor
   // view), then reorders the immediate children of that layer to match the
   // order of the view tree.
   virtual void ReorderLayers();
 
   // This reorders the immediate children of |*parent_layer| to match the
-  // order of the view tree.
+  // order of the view tree. Child layers which are owned by a view are
+  // reordered so that they are below any child layers not owned by a view.
+  // Widget::ReorderNativeViews() should be called to reorder any child layers
+  // with an associated view. Widget::ReorderNativeViews() may reorder layers
+  // below layers owned by a view.
   virtual void ReorderChildLayers(ui::Layer* parent_layer);
 
   // Input ---------------------------------------------------------------------
 
   // Called by HitTestRect() to see if this View has a custom hit test mask. If
   // the return value is true, GetHitTestMask() will be called to obtain the
   // mask. Default value is false, in which case the View will hit-test against
   // its bounds.
   virtual bool HasHitTestMask() const;
 
@@ skipping 420 matching lines @@
   // Belongs to this view, but it's reference-counted on some platforms
   // so we can't use a scoped_ptr. It's dereferenced in the destructor.
   NativeViewAccessibility* native_view_accessibility_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_