Remove the concept of user stylesheets.

Source/web/WebDocument.cpp

 /*
  * Copyright (C) 2009 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 188 matching lines @@
 WebNode WebDocument::focusedNode() const
 {
     return WebNode(constUnwrap<Document>()->focusedElement());
 }
 
 WebDocumentType WebDocument::doctype() const
 {
     return WebDocumentType(constUnwrap<Document>()->doctype());
 }
 
-void WebDocument::insertUserStyleSheet(const WebString& sourceCode, UserStyleLevel styleLevel)
+void WebDocument::insertUserStyleSheet(const WebString& sourceCode, UserStyleLevel)
+{
+    insertStyleSheet(sourceCode);
+}
+
+void WebDocument::insertStyleSheet(const WebString& sourceCode)
 {
     RefPtr<Document> document = unwrap<Document>();
     ASSERT(document);
     RefPtr<StyleSheetContents> parsedSheet = StyleSheetContents::create(*document.get());
-    parsedSheet->setIsUserStyleSheet(styleLevel == UserStyleUserLevel);
     parsedSheet->parseString(sourceCode);
-    if (parsedSheet->isUserStyleSheet())
-        document->styleEngine()->addUserSheet(parsedSheet);
-    else
-        document->styleEngine()->addAuthorSheet(parsedSheet);
+    document->styleEngine()->addAuthorSheet(parsedSheet);
 }
 
 void WebDocument::watchCSSSelectors(const WebVector<WebString>& webSelectors)
 {
     RefPtr<Document> document = unwrap<Document>();
     Vector<String> selectors;
     selectors.append(webSelectors.data(), webSelectors.size());
     CSSSelectorWatch::from(*document).watchCSSSelectors(selectors);
 }
 
@@ skipping 84 matching lines @@
     m_private = elem;
     return *this;
 }
 
 WebDocument::operator PassRefPtr<Document>() const
 {
     return toDocument(m_private.get());
 }
 
 } // namespace blink