Have ElementTraversal::firstWithin() take a reference

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 3388b1d232304afa36428ef56a5ff40e83fa8307..7aa25e358dcc70ecbb94fabc2d0ab6e93c10172c 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -675,7 +675,7 @@ void Document::childrenChanged(bool changedByParser, Node* beforeChange, Node* a
 {
     ContainerNode::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
 
-    Element* newDocumentElement = ElementTraversal::firstWithin(this);
+    Element* newDocumentElement = ElementTraversal::firstWithin(*this);
     if (newDocumentElement == m_documentElement)
         return;
     m_documentElement = newDocumentElement;
@@ -2673,7 +2673,7 @@ void Document::updateBaseURL()
     if (!equalIgnoringFragmentIdentifier(oldBaseURL, m_baseURL)) {
         // Base URL change changes any relative visited links.
         // FIXME: There are other URLs in the tree that would need to be re-evaluated on dynamic base URL change. Style should be invalidated too.
-        for (Element* element = ElementTraversal::firstWithin(this); element; element = ElementTraversal::next(*element)) {
+        for (Element* element = ElementTraversal::firstWithin(*this); element; element = ElementTraversal::next(*element)) {
             if (isHTMLAnchorElement(element))
                 toHTMLAnchorElement(element)->invalidateCachedVisitedLinkHash();
         }
@@ -2691,7 +2691,7 @@ void Document::processBaseElement()
     // Find the first href attribute in a base element and the first target attribute in a base element.
     const AtomicString* href = 0;
     const AtomicString* target = 0;
-    for (Element* element = ElementTraversal::firstWithin(this); element && (!href || !target); element = ElementTraversal::next(*element)) {
+    for (Element* element = ElementTraversal::firstWithin(*this); element && (!href || !target); element = ElementTraversal::next(*element)) {
         if (element->hasTagName(baseTag)) {
             if (!href) {
                 const AtomicString& value = element->fastGetAttribute(hrefAttr);