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

Source/core/html/HTMLFieldSetElement.cpp

Index: Source/core/html/HTMLFieldSetElement.cpp
diff --git a/Source/core/html/HTMLFieldSetElement.cpp b/Source/core/html/HTMLFieldSetElement.cpp
index 66ef5374076f0661202553386dc562bc4c4f5e91..f031a7b86919d60b47918cd96c4bf536ac0cb85c 100644
--- a/Source/core/html/HTMLFieldSetElement.cpp
+++ b/Source/core/html/HTMLFieldSetElement.cpp
@@ -52,7 +52,7 @@ PassRefPtr<HTMLFieldSetElement> HTMLFieldSetElement::create(const QualifiedName&
 
 void HTMLFieldSetElement::invalidateDisabledStateUnder(Element* base)
 {
-    for (Element* element = ElementTraversal::firstWithin(base); element; element = ElementTraversal::next(element, base)) {
+    for (Element* element = ElementTraversal::firstWithin(base); element; element = ElementTraversal::next(*element, base)) {
         if (element->isFormControlElement())
             toHTMLFormControlElement(element)->ancestorDisabledStateWasChanged();
     }
@@ -114,7 +114,7 @@ void HTMLFieldSetElement::refreshElementsIfNeeded() const
 
     m_associatedElements.clear();
 
-    for (Element* element = ElementTraversal::firstWithin(this); element; element = ElementTraversal::next(element, this)) {
+    for (Element* element = ElementTraversal::firstWithin(this); element; element = ElementTraversal::next(*element, this)) {
         if (element->hasTagName(objectTag)) {
             m_associatedElements.append(toHTMLObjectElement(element));
             continue;