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 6e5f1a2247944be08431a2545a967e758c5e537b..9eab5f6d254c577af27cfe1a77cdb1957ab6475f 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);