Have ElementTraversal::firstWithin() take a reference

Source/core/dom/shadow/ElementShadow.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 304 matching lines @@
     pool.distributeTo(insertionPoint, this);
 }
 
 const SelectRuleFeatureSet& ElementShadow::ensureSelectFeatureSet()
 {
     if (!m_needsSelectFeatureSet)
         return m_selectFeatures;
 
     m_selectFeatures.clear();
     for (ShadowRoot* root = oldestShadowRoot(); root; root = root->youngerShadowRoot())
-        collectSelectFeatureSetFrom(root);
+        collectSelectFeatureSetFrom(*root);
     m_needsSelectFeatureSet = false;
     return m_selectFeatures;
 }
 
-void ElementShadow::collectSelectFeatureSetFrom(ShadowRoot* root)
+void ElementShadow::collectSelectFeatureSetFrom(ShadowRoot& root)
 {
-    if (!root->containsShadowRoots() && !root->containsContentElements())
+    if (!root.containsShadowRoots() && !root.containsContentElements())
         return;
 
-    for (Element* element = ElementTraversal::firstWithin(root); element; element = ElementTraversal::next(*element, root)) {
+    for (Element* element = ElementTraversal::firstWithin(root); element; element = ElementTraversal::next(*element, &root)) {
         if (ElementShadow* shadow = element->shadow())
             m_selectFeatures.add(shadow->ensureSelectFeatureSet());
         if (!isHTMLContentElement(element))
             continue;
         const CSSSelectorList& list = toHTMLContentElement(element)->selectorList();
         for (const CSSSelector* selector = list.first(); selector; selector = CSSSelectorList::next(selector)) {
             for (const CSSSelector* component = selector; component; component = component->tagHistory())
                 m_selectFeatures.collectFeaturesFromSelector(component);
         }
     }
@@ skipping 17 matching lines @@
 
 void ElementShadow::clearDistribution()
 {
     m_nodeToInsertionPoints.clear();
 
     for (ShadowRoot* root = youngestShadowRoot(); root; root = root->olderShadowRoot())
         root->setShadowInsertionPointOfYoungerShadowRoot(0);
 }
 
 } // namespace