Add toHTMLHeadElement(), and use it.

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 2278 matching lines @@
     else
         documentElement()->appendChild(newBody.release(), es);
 }
 
 HTMLHeadElement* Document::head()
 {
     Node* de = documentElement();
     if (!de)
         return 0;
 
-    for (Node* e = de->firstChild(); e; e = e->nextSibling())
-        if (e->hasTagName(headTag))
-            return static_cast<HTMLHeadElement*>(e);
-
+    for (Node* node = de->firstChild(); node; node = node->nextSibling()) {
+        if (node->hasTagName(headTag))
+            return toHTMLHeadElement(node);
+    }
     return 0;
 }
 
 void Document::close()
 {
     // FIXME: We should follow the specification more closely:
     //        http://www.whatwg.org/specs/web-apps/current-work/#dom-document-close
 
     if (!scriptableDocumentParser() || !scriptableDocumentParser()->wasCreatedByScript() || !scriptableDocumentParser()->isParsing())
         return;
@@ skipping 3138 matching lines @@
 {
     return DocumentLifecycleNotifier::create(this);
 }
 
 DocumentLifecycleNotifier* Document::lifecycleNotifier()
 {
     return static_cast<DocumentLifecycleNotifier*>(ScriptExecutionContext::lifecycleNotifier());
 }
 
 } // namespace WebCore