Introduce toHTMLLinkElement

Source/core/page/PageSerializer.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 206 matching lines @@
         // We have to process in-line style as it might contain some resources (typically background images).
         if (element->isStyledElement())
             retrieveResourcesForProperties(element->inlineStyle(), document);
 
         if (element->hasTagName(HTMLNames::imgTag)) {
             HTMLImageElement* imageElement = toHTMLImageElement(element);
             KURL url = document->completeURL(imageElement->getAttribute(HTMLNames::srcAttr));
             CachedImage* cachedImage = imageElement->cachedImage();
             addImageToResources(cachedImage, imageElement->renderer(), url);
         } else if (element->hasTagName(HTMLNames::linkTag)) {
-            HTMLLinkElement* linkElement = static_cast<HTMLLinkElement*>(element);
+            HTMLLinkElement* linkElement = toHTMLLinkElement(element);
             if (CSSStyleSheet* sheet = linkElement->sheet()) {
                 KURL url = document->completeURL(linkElement->getAttribute(HTMLNames::hrefAttr));
                 serializeCSSStyleSheet(sheet, url);
                 ASSERT(m_resourceURLs.contains(url));
             }
         } else if (element->hasTagName(HTMLNames::styleTag)) {
             HTMLStyleElement* styleElement = toHTMLStyleElement(element);
             if (CSSStyleSheet* sheet = styleElement->sheet())
                 serializeCSSStyleSheet(sheet, KURL());
         }
@@ skipping 98 matching lines @@
     if (iter != m_blankFrameURLs.end())
         return iter->value;
     String url = "wyciwyg://frame/" + String::number(m_blankFrameCounter++);
     KURL fakeURL(ParsedURLString, url);
     m_blankFrameURLs.add(frame, fakeURL);
 
     return fakeURL;
 }
 
 }