Move highestAncestorOrSelf() from Node to NodeTraversal

Source/core/xml/XPathPath.cpp

Index: Source/core/xml/XPathPath.cpp
diff --git a/Source/core/xml/XPathPath.cpp b/Source/core/xml/XPathPath.cpp
index 9055a259f9e709b70ebf03eac0bb74161508586d..74dc33cb7b92b653468ba3ccffc04d29c976a4c9 100644
--- a/Source/core/xml/XPathPath.cpp
+++ b/Source/core/xml/XPathPath.cpp
@@ -29,6 +29,7 @@
 #include "core/xml/XPathPath.h"
 
 #include "core/dom/Document.h"
+#include "core/dom/NodeTraversal.h"
 #include "core/xml/XPathPredicate.h"
 #include "core/xml/XPathStep.h"
 #include "core/xml/XPathValue.h"
@@ -120,7 +121,7 @@ Value LocationPath::evaluate(EvaluationContext& evaluationContext) const
         if (context->inDocument())
             context = context->ownerDocument();
         else
-            context = &context->highestAncestorOrSelf();
+            context = &NodeTraversal::highestAncestorOrSelf(*context);
     }
 
     OwnPtrWillBeRawPtr<NodeSet> nodes(NodeSet::create());