Use Traversal<>::firstAncestor() API more in the code base

Source/core/html/HTMLMetaElement-in.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 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/HTMLMetaElement.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
+#include "core/html/HTMLHeadElement.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "platform/RuntimeEnabledFeatures.h"
 
 namespace blink {
 
 #define DEFINE_ARRAY_FOR_MATCHING(name, source, maxMatchLength) \
 const UChar* name; \
 const unsigned uMaxMatchLength = maxMatchLength; \
 UChar characterBuffer[uMaxMatchLength]; \
@@ skipping 401 matching lines @@
 void HTMLMetaElement::didNotifySubtreeInsertionsToDocument()
 {
     process();
 }
 
 static bool inDocumentHead(HTMLMetaElement* element)
 {
     if (!element->inDocument())
         return false;
 
-    for (Element* current = element; current; current = current->parentElement()) {
-        if (isHTMLHeadElement(*current))
-            return true;
-    }
-    return false;
+    return Traversal<HTMLHeadElement>::firstAncestor(*element);
 }
 
 void HTMLMetaElement::process()
 {
     if (!inDocument())
         return;
 
     // All below situations require a content attribute (which can be the empty string).
     const AtomicString& contentValue = fastGetAttribute(contentAttr);
     if (contentValue.isNull())
@@ skipping 31 matching lines @@
 {
     return getAttribute(http_equivAttr);
 }
 
 const AtomicString& HTMLMetaElement::name() const
 {
     return getNameAttribute();
 }
 
 }