Have NodeTraversal::nextSkippingChildren() take a reference

Source/core/html/HTMLCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 511 matching lines @@
     if (type() == DocAll && !nameShouldBeVisibleInDocumentAll(e))
         return false;
 
     return e->getNameAttribute() == name && e->getIdAttribute() != name;
 }
 
 inline Element* firstMatchingChildElement(const HTMLCollection* nodeList, ContainerNode* root)
 {
     Element* element = ElementTraversal::firstWithin(root);
     while (element && !isMatchingElement(nodeList, element))
-        element = ElementTraversal::nextSkippingChildren(element, root);
+        element = ElementTraversal::nextSkippingChildren(*element, root);
     return element;
 }
 
-inline Element* nextMatchingChildElement(const HTMLCollection* nodeList, Element* current, ContainerNode* root)
+inline Element* nextMatchingChildElement(const HTMLCollection* nodeList, Element& current, ContainerNode* root)
 {
+    Element* next = &current;
     do {
-        current = ElementTraversal::nextSkippingChildren(current, root);
-    } while (current && !isMatchingElement(nodeList, current));
-    return current;
+        next = ElementTraversal::nextSkippingChildren(*next, root);
+    } while (next && !isMatchingElement(nodeList, next));
+    return next;
 }
 
 inline Element* HTMLCollection::traverseFirstElement(unsigned& offsetInArray, ContainerNode* root) const
 {
     if (overridesItemAfter())
         return virtualItemAfter(offsetInArray, 0);
     ASSERT(!offsetInArray);
     if (shouldOnlyIncludeDirectChildren())
         return firstMatchingChildElement(static_cast<const HTMLCollection*>(this), root);
     return firstMatchingElement(static_cast<const HTMLCollection*>(this), root);
 }
 
 inline Element* HTMLCollection::traverseNextElement(unsigned& offsetInArray, Element& previous, ContainerNode* root) const
 {
     if (overridesItemAfter())
         return virtualItemAfter(offsetInArray, &previous);
     ASSERT(!offsetInArray);
     if (shouldOnlyIncludeDirectChildren())
-        return nextMatchingChildElement(this, &previous, root);
+        return nextMatchingChildElement(this, previous, root);
     return nextMatchingElement(this, previous, root);
 }
 
 inline Element* HTMLCollection::traverseForwardToOffset(unsigned offset, Element& currentElement, unsigned& currentOffset, unsigned& offsetInArray, ContainerNode* root) const
 {
     ASSERT(currentOffset < offset);
     if (overridesItemAfter()) {
         offsetInArray = m_cachedElementsArrayOffset;
         Element* next = &currentElement;
         while ((next = virtualItemAfter(offsetInArray, next))) {
             if (++currentOffset == offset)
                 return next;
         }
         return 0;
     }
     if (shouldOnlyIncludeDirectChildren()) {
         Element* next = &currentElement;
-        while ((next = nextMatchingChildElement(this, next, root))) {
+        while ((next = nextMatchingChildElement(this, *next, root))) {
             if (++currentOffset == offset)
                 return next;
         }
         return 0;
     }
     return traverseMatchingElementsForwardToOffset(this, offset, currentElement, currentOffset, root);
 }
 
 Node* HTMLCollection::namedItem(const AtomicString& name) const
 {
@@ skipping 93 matching lines @@
 
 void HTMLCollection::append(NodeCacheMap& map, const AtomicString& key, Element* element)
 {
     OwnPtr<Vector<Element*> >& vector = map.add(key.impl(), nullptr).iterator->value;
     if (!vector)
         vector = adoptPtr(new Vector<Element*>);
     vector->append(element);
 }
 
 } // namespace WebCore