Use StringBuilder::appendLiteral() / StringBuilder::append(char) when possible

Source/web/tests/LocaleICUTest.cpp

 /*
  * Copyright (C) 2012 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 43 matching lines @@
                 return false;
             for (unsigned index = 0; index < m_labels.size(); ++index)
                 if (m_labels[index] != other.m_labels[index])
                     return false;
             return true;
         }
 
         String toString() const
         {
             StringBuilder builder;
-            builder.append("labels(");
+            builder.appendLiteral("labels(");
             for (unsigned index = 0; index < m_labels.size(); ++index) {
                 if (index)
-                    builder.append(", ");
+                    builder.appendLiteral(", ");
                 builder.append('"');
                 builder.append(m_labels[index]);
                 builder.append('"');
             }
             builder.append(')');
             return builder.toString();
         }
 
     private:
         Vector<String> m_labels;
@@ skipping 195 matching lines @@
     // Test some of major locales.
     testNumbers("ar");
     testNumbers("de_DE");
     testNumbers("es_ES");
     testNumbers("ja_JP");
     testNumbers("ko_KR");
     testNumbers("zh_CN");
     testNumbers("zh_HK");
     testNumbers("zh_TW");
 }