Revert of Remove StringBuilder::appendLiteral.

third_party/WebKit/Source/core/css/CSSStyleSheet.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 312 matching lines @@
         if (m_childRuleCSSOMWrappers[index])
             m_childRuleCSSOMWrappers[index]->setParentStyleSheet(0);
         m_childRuleCSSOMWrappers.remove(index);
     }
 }
 
 int CSSStyleSheet::addRule(const String& selector, const String& style, int index, ExceptionState& exceptionState)
 {
     StringBuilder text;
     text.append(selector);
-    text.append(" { ");
+    text.appendLiteral(" { ");
     text.append(style);
     if (!style.isEmpty())
         text.append(' ');
     text.append('}');
     insertRule(text.toString(), index, exceptionState);
 
     // As per Microsoft documentation, always return -1.
     return -1;
 }
 
@@ skipping 96 matching lines @@
     visitor->trace(m_mediaQueries);
     visitor->trace(m_ownerNode);
     visitor->trace(m_ownerRule);
     visitor->trace(m_mediaCSSOMWrapper);
     visitor->trace(m_childRuleCSSOMWrappers);
     visitor->trace(m_ruleListCSSOMWrapper);
     StyleSheet::trace(visitor);
 }
 
 } // namespace blink