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

Source/core/testing/Internals.h

Index: Source/core/testing/Internals.h
diff --git a/Source/core/testing/Internals.h b/Source/core/testing/Internals.h
index b82efb1f8ea15b5158ab3edf9d84e5fb06614773..c8c434de495a7e54f338aa7880200c09ab750171 100644
--- a/Source/core/testing/Internals.h
+++ b/Source/core/testing/Internals.h
@@ -52,6 +52,7 @@ class InternalSettings;
 class Node;
 class Page;
 class PagePopupController;
+class PaintOrderLists;
 class Range;
 class ScriptExecutionContext;
 class ShadowRoot;
@@ -221,6 +222,10 @@ public:
     };
     String layerTreeAsText(Document*, unsigned flags, ExceptionCode&) const;
     String layerTreeAsText(Document*, ExceptionCode&) const;
+
+    String paintOrderListsAsText(Element* document, ExceptionCode& ec);
+    PassRefPtr<PaintOrderLists> paintOrderLists(Element* element, ExceptionCode& ec);
+
     String repaintRectsAsText(Document*, ExceptionCode&) const;
     String scrollingStateTreeAsText(Document*, ExceptionCode&) const;
     String mainThreadScrollingReasons(Document*, ExceptionCode&) const;