Revert of Remove StringBuilder::appendLiteral.

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/CSSNamespaceRule.h"
 
 #include "core/css/CSSMarkup.h"
 #include "core/css/StyleRuleNamespace.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 CSSNamespaceRule::CSSNamespaceRule(StyleRuleNamespace* namespaceRule, CSSStyleSheet* parent)
     : CSSRule(parent)
     , m_namespaceRule(namespaceRule)
 {
 }
 
 CSSNamespaceRule::~CSSNamespaceRule()
 {
 }
 
 String CSSNamespaceRule::cssText() const
 {
     StringBuilder result;
-    result.append("@namespace ");
+    result.appendLiteral("@namespace ");
     serializeIdentifier(prefix(), result);
     if (!prefix().isEmpty())
-        result.append(" ");
-    result.append("url(");
+        result.appendLiteral(" ");
+    result.appendLiteral("url(");
     result.append(serializeString(namespaceURI()));
-    result.append(");");
+    result.appendLiteral(");");
     return result.toString();
 }
 
 AtomicString CSSNamespaceRule::namespaceURI() const
 {
     return m_namespaceRule->uri();
 }
 
 AtomicString CSSNamespaceRule::prefix() const
 {
     return m_namespaceRule->prefix();
 }
 
 DEFINE_TRACE(CSSNamespaceRule)
 {
     visitor->trace(m_namespaceRule);
     CSSRule::trace(visitor);
 }
 
 } // namespace blink