List marker pseudo elements.

Source/core/css/CSSTestHelper.h

 /*
  * Copyright (c) 2014, 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 33 matching lines @@
 // helper.addCSSRule("body { color: red} #a { position: absolute }");
 // RuleSet& ruleSet = helper.ruleSet();
 // ... examine RuleSet to find the rule and test properties on it.
 
 class CSSTestHelper {
 public:
     CSSTestHelper();
     ~CSSTestHelper();
 
     void addCSSRules(const char* ruleText);
+    void tryAddCSSRules(const char* ruleText);
+
     RuleSet& ruleSet();
 
 private:
     RefPtrWillBePersistent<Document> m_document;
     RefPtrWillBePersistent<CSSStyleSheet> m_styleSheet;
 };
 
 } // namespace blink
 
 #endif // CSSTestHelper_h