Consistently use ElementTraversal API when looking for an Element

Source/core/html/HTMLTableSectionElement.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2010 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/html/HTMLTableSectionElement.h"
 
 #include "HTMLNames.h"
 #include "bindings/v8/ExceptionState.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/html/HTMLCollection.h"
 #include "core/html/HTMLTableElement.h"
 #include "core/html/HTMLTableRowElement.h"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
 inline HTMLTableSectionElement::HTMLTableSectionElement(const QualifiedName& tagName, Document& document)
@@ skipping 48 matching lines @@
     if (index >= 0 && index < numRows) {
         RefPtr<Element> row = children->item(index);
         HTMLElement::removeChild(row.get(), exceptionState);
     } else {
         exceptionState.throwDOMException(IndexSizeError, "The provided index (" + String::number(index) + " is outside the range [-1, " + String::number(numRows) + "].");
     }
 }
 
 int HTMLTableSectionElement::numRows() const
 {
-    int rows = 0;
-    const Node *n = firstChild();
-    while (n) {
-        if (n->hasTagName(trTag))
-            rows++;
-        n = n->nextSibling();
+    int rowCount = 0;
+    for (const Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
+        if (child->hasTagName(trTag))
+            ++rowCount;
     }
-
-    return rows;
+    return rowCount;
 }
 
 PassRefPtr<HTMLCollection> HTMLTableSectionElement::rows()
 {
     return ensureCachedHTMLCollection(TSectionRows);
 }
 
 }