Split NonDocumentTypeChildNode from ChildNode

Source/core/dom/NonDocumentTypeChildNode.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef ChildNode_h
-#define ChildNode_h
+#ifndef NonDocumentTypeChildNode_h
+#define NonDocumentTypeChildNode_h
 
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/Node.h"
 
 namespace blink {
 
-class ChildNode {
+class NonDocumentTypeChildNode {
 public:
     static Element* previousElementSibling(Node& node)
     {
         return ElementTraversal::previousSibling(node);
     }
 
     static Element* nextElementSibling(Node& node)
     {
         return ElementTraversal::nextSibling(node);
     }
-
-    static void remove(Node& node, ExceptionState& exceptionState)
-    {
-        return node.remove(exceptionState);
-    }
 };
 
 } // namespace blink
 
-#endif // ChildNode_h
+#endif // NonDocumentTypeChildNode_h