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

Source/core/accessibility/AXRenderObject.cpp

Index: Source/core/accessibility/AXRenderObject.cpp
diff --git a/Source/core/accessibility/AXRenderObject.cpp b/Source/core/accessibility/AXRenderObject.cpp
index db6572a9e3037fb0993ca35ad39df3c90e25359d..3b3101c110e919c13885a38d827d28f071f6d098 100644
--- a/Source/core/accessibility/AXRenderObject.cpp
+++ b/Source/core/accessibility/AXRenderObject.cpp
@@ -2196,7 +2196,7 @@ void AXRenderObject::addImageMapChildren()
     if (!map)
         return;
 
-    for (Element* current = ElementTraversal::firstWithin(map); current; current = ElementTraversal::next(current, map)) {
+    for (Element* current = ElementTraversal::firstWithin(map); current; current = ElementTraversal::next(*current, map)) {
         // add an <area> element for this child if it has a link
         if (isHTMLAreaElement(current) && current->isLink()) {
             AXImageMapLink* areaObject = toAXImageMapLink(axObjectCache()->getOrCreate(ImageMapLinkRole));