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

Source/core/editing/BreakBlockquoteCommand.cpp

Index: Source/core/editing/BreakBlockquoteCommand.cpp
diff --git a/Source/core/editing/BreakBlockquoteCommand.cpp b/Source/core/editing/BreakBlockquoteCommand.cpp
index 906492356f816e08db201323b9e848c0a86aa01d..baf29956fb5013d945da3a843bcdf14b59e73904 100644
--- a/Source/core/editing/BreakBlockquoteCommand.cpp
+++ b/Source/core/editing/BreakBlockquoteCommand.cpp
@@ -105,18 +105,19 @@ void BreakBlockquoteCommand::doApply()
 
     // startNode is the first node that we need to move to the new blockquote.
     Node* startNode = pos.deprecatedNode();
+    ASSERT(startNode);
 
     // Split at pos if in the middle of a text node.
     if (startNode->isTextNode()) {
         Text* textNode = toText(startNode);
         if ((unsigned)pos.deprecatedEditingOffset() >= textNode->length()) {
-            startNode = NodeTraversal::next(startNode);
+            startNode = NodeTraversal::next(*startNode);
             ASSERT(startNode);
         } else if (pos.deprecatedEditingOffset() > 0)
             splitTextNode(textNode, pos.deprecatedEditingOffset());
     } else if (pos.deprecatedEditingOffset() > 0) {
         Node* childAtOffset = startNode->childNode(pos.deprecatedEditingOffset());
-        startNode = childAtOffset ? childAtOffset : NodeTraversal::next(startNode);
+        startNode = childAtOffset ? childAtOffset : NodeTraversal::next(*startNode);
         ASSERT(startNode);
     }