Pass rootNode by reference when constructing node lists / collections

Source/core/html/HTMLCollection.h

Index: Source/core/html/HTMLCollection.h
diff --git a/Source/core/html/HTMLCollection.h b/Source/core/html/HTMLCollection.h
index b1047642e92e4c81b509e0d41433d1af7e7c4e28..0c916440a01bbd03660fa337b1c9ff428a488b63 100644
--- a/Source/core/html/HTMLCollection.h
+++ b/Source/core/html/HTMLCollection.h
@@ -40,7 +40,7 @@ public:
         DoesNotOverrideItemAfter,
     };
 
-    static PassRefPtr<HTMLCollection> create(ContainerNode* base, CollectionType);
+    static PassRefPtr<HTMLCollection> create(ContainerNode& base, CollectionType);
     virtual ~HTMLCollection();
     virtual void invalidateCache(Document* oldDocument = 0) const OVERRIDE;
 
@@ -63,7 +63,7 @@ public:
     Element* traverseForwardToOffset(unsigned offset, Element& currentElement, unsigned& currentOffset, const ContainerNode& root) const;
 
 protected:
-    HTMLCollection(ContainerNode* base, CollectionType, ItemAfterOverrideType);
+    HTMLCollection(ContainerNode& base, CollectionType, ItemAfterOverrideType);
 
     bool overridesItemAfter() const { return m_overridesItemAfter; }
     virtual Element* virtualItemAfter(Element*) const;