Add an intermediate function to generate 2 paint-order lists.

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 1524 matching lines @@
     }
 
     return document->isPageBoxVisible(pageNumber);
 }
 
 String Internals::layerTreeAsText(Document* document, ExceptionCode& ec) const
 {
     return layerTreeAsText(document, 0, ec);
 }
 
+PassRefPtr<NodeList> Internals::paintOrderListBeforePromote(Element* element, ExceptionCode& ec)
+{
+    if (!element) {
+        ec = INVALID_ACCESS_ERR;
+        return 0;
+    }
+
+    element->document()->updateLayout();
+
+    RenderObject* renderer = element->renderer();
+    if (!renderer || !renderer->isBox()) {
+        ec = INVALID_ACCESS_ERR;
+        return 0;
+    }
+
+    RenderLayer* layer = toRenderBox(renderer)->layer();
+    if (!layer) {
+        ec = INVALID_ACCESS_ERR;
+        return 0;
+    }
+
+    return layer->paintOrderListBeforePromote();
+}
+
+PassRefPtr<NodeList> Internals::paintOrderListAfterPromote(Element* element, ExceptionCode& ec)
+{
+    if (!element) {
+        ec = INVALID_ACCESS_ERR;
+        return 0;
+    }
+
+    element->document()->updateLayout();
+
+    RenderObject* renderer = element->renderer();
+    if (!renderer || !renderer->isBox()) {
+        ec = INVALID_ACCESS_ERR;
+        return 0;
+    }
+
+    RenderLayer* layer = toRenderBox(renderer)->layer();
+    if (!layer) {
+        ec = INVALID_ACCESS_ERR;
+        return 0;
+    }
+
+    return layer->paintOrderListAfterPromote();
+}
+
 String Internals::layerTreeAsText(Document* document, unsigned flags, ExceptionCode& ec) const
 {
     if (!document || !document->frame()) {
         ec = INVALID_ACCESS_ERR;
         return String();
     }
 
     LayerTreeFlags layerTreeFlags = 0;
     if (flags & LAYER_TREE_INCLUDES_VISIBLE_RECTS)
         layerTreeFlags |= LayerTreeFlagsIncludeVisibleRects;
@@ skipping 379 matching lines @@
 
     RenderObject* renderer = select->renderer();
     if (!renderer->isMenuList())
         return false;
 
     RenderMenuList* menuList = toRenderMenuList(renderer);
     return menuList->popupIsVisible();
 }
 
 }