Have NodeTraversal::nextSkippingChildren() take a reference

Source/core/editing/CompositeEditCommand.cpp

Index: Source/core/editing/CompositeEditCommand.cpp
diff --git a/Source/core/editing/CompositeEditCommand.cpp b/Source/core/editing/CompositeEditCommand.cpp
index 98e8af33e8ad90cf68acbd0ff955a0b0ce0bb379..4db2fe86342c16860200307aa8539f6c2eb0c379 100644
--- a/Source/core/editing/CompositeEditCommand.cpp
+++ b/Source/core/editing/CompositeEditCommand.cpp
@@ -1015,7 +1015,7 @@ void CompositeEditCommand::cloneParagraphUnderNewElement(Position& start, Positi
         }
 
         RefPtr<Node> startNode = start.deprecatedNode();
-        for (RefPtr<Node> node = NodeTraversal::nextSkippingChildren(startNode.get(), outerNode.get()); node; node = NodeTraversal::nextSkippingChildren(node.get(), outerNode.get())) {
+        for (RefPtr<Node> node = NodeTraversal::nextSkippingChildren(*startNode, outerNode.get()); node; node = NodeTraversal::nextSkippingChildren(*node, outerNode.get())) {
             // Move lastNode up in the tree as much as node was moved up in the
             // tree by NodeTraversal::nextSkippingChildren, so that the relative depth between
             // node and the original start node is maintained in the clone.