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

Source/core/page/TouchDisambiguation.cpp

Index: Source/core/page/TouchDisambiguation.cpp
diff --git a/Source/core/page/TouchDisambiguation.cpp b/Source/core/page/TouchDisambiguation.cpp
index 019e61fdcce47307dd0dab6dce909871fd78d9bf..248c498cf29b5f0d78045cb2a1be7e1621563de6 100644
--- a/Source/core/page/TouchDisambiguation.cpp
+++ b/Source/core/page/TouchDisambiguation.cpp
@@ -63,7 +63,7 @@ static IntRect boundingBoxForEventNodes(Node* eventNode)
             continue;
         }
         result.unite(node->pixelSnappedBoundingBox());
-        node = NodeTraversal::next(node, eventNode);
+        node = NodeTraversal::next(*node, eventNode);
     }
     return eventNode->document().view()->contentsToWindow(result);
 }