Introduce ChildNode IDL interface

Source/core/dom/ChildNode.idl

Index: Source/core/dom/ChildNode.idl
diff --git a/Source/core/css/StyleSheetList.idl b/Source/core/dom/ChildNode.idl
similarity index 69%
copy from Source/core/css/StyleSheetList.idl
copy to Source/core/dom/ChildNode.idl
index 390e2c9717019f07e0b3226476a87372b795826b..d08786b750c01334078810b77ab522188562c928 100644
--- a/Source/core/css/StyleSheetList.idl
+++ b/Source/core/dom/ChildNode.idl
@@ -1,6 +1,8 @@
 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
+ * Copyright (C) 2013 Samsung Electronics. All rights reserved.
+ * 
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -18,12 +20,13 @@
  * Boston, MA 02110-1301, USA.
  */
 
-// Introduced in DOM Level 2:
-[
-    GenerateIsReachable=document,
-] interface StyleSheetList {
-    readonly attribute unsigned long    length;
-    getter StyleSheet         item([Default=Undefined] optional unsigned long index);
-    [ImplementedAs=anonymousNamedGetter, NotEnumerable] getter CSSStyleSheet (DOMString name);
+[NoInterfaceObject]
+interface ChildNode {
+    [PerWorldBindings] readonly attribute Element previousElementSibling;
+    [PerWorldBindings] readonly attribute Element nextElementSibling;
+    [RaisesException] void remove();
 };
 
+DocumentType implements ChildNode;
+Element implements ChildNode;
+CharacterData implements ChildNode;