Have HTMLTableRowsCollection::item() return an HTMLTableRowElement*

Source/core/html/HTMLTableRowsCollection.h

 /*
  * Copyright (C) 2008 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 12 matching lines @@
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef HTMLTableRowsCollection_h
 #define HTMLTableRowsCollection_h
 
 #include "core/html/HTMLCollection.h"
+#include "core/html/HTMLTableRowElement.h"
 
 namespace blink {
 
 class HTMLTableElement;
 class HTMLTableRowElement;
 
 class HTMLTableRowsCollection FINAL : public HTMLCollection {
 public:
     static PassRefPtrWillBeRawPtr<HTMLTableRowsCollection> create(ContainerNode&, CollectionType);
 
+    HTMLTableRowElement* item(unsigned offset) const { return toHTMLTableRowElement(HTMLCollection::item(offset)); }
+
     static HTMLTableRowElement* rowAfter(HTMLTableElement&, HTMLTableRowElement*);
     static HTMLTableRowElement* lastRow(HTMLTableElement&);
 
 private:
     explicit HTMLTableRowsCollection(ContainerNode&);
 
     virtual Element* virtualItemAfter(Element*) const OVERRIDE;
 };
 
 DEFINE_TYPE_CASTS(HTMLTableRowsCollection, LiveNodeListBase, collection, collection->type() == TableRows, collection.type() == TableRows);
 
 } // namespace
 
 #endif