Set up scroll and clip parents

Source/core/testing/Internals.idl

Index: Source/core/testing/Internals.idl
diff --git a/Source/core/testing/Internals.idl b/Source/core/testing/Internals.idl
index a7c648d8fc8f954ce8a6470261320af4446dfb47..6ff369cef1a1683bec2e5bf6675eae3700f428f6 100644
--- a/Source/core/testing/Internals.idl
+++ b/Source/core/testing/Internals.idl
@@ -186,6 +186,12 @@
     const unsigned short COMPOSITED_SCROLLING_ALWAYS_OFF = 2;
     [RaisesException] void setNeedsCompositedScrolling(Element element, unsigned short value);
 
+    [RaisesException] boolean isScrollParent(Element child, Element parent);
+    [RaisesException] boolean isClipParent(Element child, Element parent);
+
+    [RaisesException] ClientRect scrollClip(Element element);
+    [RaisesException] ClientRect ancestorScrollClip(Element element);
+
     [RaisesException] DOMString scrollingStateTreeAsText(Document document);
     [RaisesException] DOMString mainThreadScrollingReasons(Document document);
     [RaisesException] ClientRectList nonFastScrollableRects(Document document);