Move highestAncestorOrSelf() from Node to NodeTraversal

Source/core/dom/NodeTraversal.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2014 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef NodeTraversal_h
 #define NodeTraversal_h
 
+#include "core/dom/ContainerNode.h"
 #include "core/dom/Node.h"
 
 namespace blink {
 
 class NodeTraversal {
 public:
     // Does a pre-order traversal of the tree to find the next node after this one.
     // This uses the same order that tags appear in the source file. If the stayWithin
     // argument is non-null, the traversal will stop once the specified node is reached.
     // This can be used to restrict traversal to a particular sub-tree.
@@ skipping 21 matching lines @@
     // Like previous, but visits parents before their children.
     static Node* previousPostOrder(const Node&, const Node* stayWithin = 0);
 
     // Pre-order traversal including the pseudo-elements.
     static Node* previousIncludingPseudo(const Node&, const Node* stayWithin = 0);
     static Node* nextIncludingPseudo(const Node&, const Node* stayWithin = 0);
     static Node* nextIncludingPseudoSkippingChildren(const Node&, const Node* stayWithin = 0);
 
     static Node* nextAncestorSibling(const Node&);
     static Node* nextAncestorSibling(const Node&, const Node* stayWithin);
+    static Node& highestAncestorOrSelf(Node&);
 
 private:
     template <class NodeType>
     static Node* traverseNextTemplate(NodeType&);
     template <class NodeType>
     static Node* traverseNextTemplate(NodeType&, const Node* stayWithin);
 };
 
 template <class NodeType>
 inline Node* NodeTraversal::traverseNextTemplate(NodeType& current)
@@ skipping 26 matching lines @@
 
 inline Node* NodeTraversal::nextSkippingChildren(const Node& current, const Node* stayWithin)
 {
     if (current == stayWithin)
         return 0;
     if (current.nextSibling())
         return current.nextSibling();
     return nextAncestorSibling(current, stayWithin);
 }
 
+inline Node& NodeTraversal::highestAncestorOrSelf(Node& current)
+{
+    Node* highest = &current;
+    while (highest->parentNode())
+        highest = highest->parentNode();
+    return *highest;
+}
+
 } // namespace blink
 
 #endif