Add Element::subResourceAttributeName() virtual function

Source/core/html/HTMLLinkElement.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, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google 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 387 matching lines @@
 bool HTMLLinkElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name().localName() == hrefAttr || HTMLElement::isURLAttribute(attribute);
 }
 
 bool HTMLLinkElement::hasLegalLinkAttribute(const QualifiedName& name) const
 {
     return name == hrefAttr || HTMLElement::hasLegalLinkAttribute(name);
 }
 
+const QualifiedName& HTMLLinkElement::subResourceAttributeName() const
+{
+    // If the link element is not css, ignore it.
+    if (equalIgnoringCase(getAttribute(typeAttr), "text/css")) {
+        // FIXME: Add support for extracting links of sub-resources which
+        // are inside style-sheet such as @import, @font-face, url(), etc.
+        return hrefAttr;
+    }
+    return HTMLElement::subResourceAttributeName();
+}
+
 KURL HTMLLinkElement::href() const
 {
     return document().completeURL(getAttribute(hrefAttr));
 }
 
 const AtomicString& HTMLLinkElement::rel() const
 {
     return getAttribute(relAttr);
 }
 
@@ skipping 291 matching lines @@
 void LinkStyle::ownerRemoved()
 {
     if (m_sheet)
         clearSheet();
 
     if (styleSheetIsLoading())
         removePendingSheet(RemovePendingSheetNotifyLater);
 }
 
 } // namespace WebCore