Have ElementTraversal / NodeTraversal's next() methods take a reference

Source/core/xml/XPathStep.cpp

Index: Source/core/xml/XPathStep.cpp
diff --git a/Source/core/xml/XPathStep.cpp b/Source/core/xml/XPathStep.cpp
index d7bca15681865e6de699116e3b0f211173762249..d08013e005eb5561c8ed82d18384eb68f0f47f97 100644
--- a/Source/core/xml/XPathStep.cpp
+++ b/Source/core/xml/XPathStep.cpp
@@ -254,7 +254,7 @@ void Step::nodesInAxis(Node* context, NodeSet& nodes) const
             if (context->isAttributeNode()) // In XPath model, attribute nodes do not have children.
                 return;
 
-            for (Node* n = context->firstChild(); n; n = NodeTraversal::next(n, context))
+            for (Node* n = context->firstChild(); n; n = NodeTraversal::next(*n, context))
                 if (nodeMatches(n, DescendantAxis, m_nodeTest))
                     nodes.append(n);
             return;
@@ -305,7 +305,7 @@ void Step::nodesInAxis(Node* context, NodeSet& nodes) const
         case FollowingAxis:
             if (context->isAttributeNode()) {
                 Node* p = toAttr(context)->ownerElement();
-                while ((p = NodeTraversal::next(p))) {
+                while ((p = NodeTraversal::next(*p))) {
                     if (nodeMatches(p, FollowingAxis, m_nodeTest))
                         nodes.append(p);
                 }
@@ -314,7 +314,7 @@ void Step::nodesInAxis(Node* context, NodeSet& nodes) const
                     for (Node* n = p->nextSibling(); n; n = n->nextSibling()) {
                         if (nodeMatches(n, FollowingAxis, m_nodeTest))
                             nodes.append(n);
-                        for (Node* c = n->firstChild(); c; c = NodeTraversal::next(c, n))
+                        for (Node* c = n->firstChild(); c; c = NodeTraversal::next(*c, n))
                             if (nodeMatches(c, FollowingAxis, m_nodeTest))
                                 nodes.append(c);
                     }
@@ -374,7 +374,7 @@ void Step::nodesInAxis(Node* context, NodeSet& nodes) const
             if (context->isAttributeNode()) // In XPath model, attribute nodes do not have children.
                 return;
 
-            for (Node* n = context->firstChild(); n; n = NodeTraversal::next(n, context))
+            for (Node* n = context->firstChild(); n; n = NodeTraversal::next(*n, context))
             if (nodeMatches(n, DescendantOrSelfAxis, m_nodeTest))
                 nodes.append(n);
             return;