StyleSheetContents doesn't need a set of clients.

sky/engine/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 97 matching lines @@
     String cssText =
         "link, import, meta, script, style, template, title {\n"
         "    display: none;\n"
         "}\n"
         "a {\n"
         "    color: blue;\n"
         "    display: inline;\n"
         "    text-decoration: underline;\n"
         "}\n";
 
-
-    styleSheet = StyleSheetContents::create(CSSParserContext(0));
+    styleSheet = StyleSheetContents::create(0, CSSParserContext(0));
     styleSheet->parseString(cssText);
 
     ruleSet = RuleSet::create();
     ruleSet->addRulesFromSheet(styleSheet.get());
 
     return *ruleSet;
 }
 
 StyleResolver::StyleResolver(Document& document)
     : m_document(document)
@@ skipping 782 matching lines @@
 bool StyleResolver::mediaQueryAffectedByViewportChange() const
 {
     for (unsigned i = 0; i < m_viewportDependentMediaQueryResults.size(); ++i) {
         if (m_medium->eval(m_viewportDependentMediaQueryResults[i]->expression()) != m_viewportDependentMediaQueryResults[i]->result())
             return true;
     }
     return false;
 }
 
 } // namespace blink