Introduce HasHTMLTagName functor and use it with ElementTraversal

Source/core/html/HTMLTableRowElement.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, 2007, 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
@@ skipping 63 matching lines @@
     int rIndex = 0;
 
     if (HTMLTableSectionElement* head = toHTMLTableElement(table)->tHead()) {
         for (HTMLTableRowElement* row = Traversal<HTMLTableRowElement>::firstChild(*head); row; row = Traversal<HTMLTableRowElement>::nextSibling(*row)) {
             if (row == this)
                 return rIndex;
             ++rIndex;
         }
     }
 
-    for (HTMLElement* child = Traversal<HTMLElement>::firstChild(*table); child; child = Traversal<HTMLElement>::nextSibling(*child)) {
-        if (child->hasTagName(tbodyTag)) {
-            HTMLTableSectionElement* section = toHTMLTableSectionElement(child);
-            for (HTMLTableRowElement* row = Traversal<HTMLTableRowElement>::firstChild(*section); row; row = Traversal<HTMLTableRowElement>::nextSibling(*row)) {
-                if (row == this)
-                    return rIndex;
-                ++rIndex;
-            }
+    for (HTMLElement* tbody = Traversal<HTMLElement>::firstChild(*table, HasHTMLTagName(tbodyTag)); tbody; tbody = Traversal<HTMLElement>::nextSibling(*tbody, HasHTMLTagName(tbodyTag))) {
+        for (HTMLTableRowElement* row = Traversal<HTMLTableRowElement>::firstChild(*tbody); row; row = Traversal<HTMLTableRowElement>::nextSibling(*row)) {
+            if (row == this)
+                return rIndex;
+            ++rIndex;
         }
     }
 
     if (HTMLTableSectionElement* foot = toHTMLTableElement(table)->tFoot()) {
         for (HTMLTableRowElement* row = Traversal<HTMLTableRowElement>::firstChild(*foot); row; row = Traversal<HTMLTableRowElement>::nextSibling(*row)) {
             if (row == this)
                 return rIndex;
             ++rIndex;
         }
     }
@@ skipping 51 matching lines @@
         exceptionState.throwDOMException(IndexSizeError, "The value provided (" + String::number(index) + ") is outside the range [0, " + String::number(numCells) + ").");
     }
 }
 
 PassRefPtrWillBeRawPtr<HTMLCollection> HTMLTableRowElement::cells()
 {
     return ensureCachedCollection<HTMLCollection>(TRCells);
 }
 
 }