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

Source/platform/text/DateTimeFormat.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:
  * 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 238 matching lines @@
 {
     if (literal.length() <= 0)
         return;
 
     if (literal.find(isASCIIAlphabetOrQuote) == kNotFound) {
         buffer.append(literal);
         return;
     }
 
     if (literal.find('\'') == kNotFound) {
-        buffer.append("'");
+        buffer.append('\'');
         buffer.append(literal);
-        buffer.append("'");
+        buffer.append('\'');
         return;
     }
 
     for (unsigned i = 0; i < literal.length(); ++i) {
         if (literal[i] == '\'') {
-            buffer.append("''");
+            buffer.appendLiteral("''");
         } else {
             String escaped = literal.substring(i);
             escaped.replace("'", "''");
-            buffer.append("'");
+            buffer.append('\'');
             buffer.append(escaped);
-            buffer.append("'");
+            buffer.append('\'');
             return;
         }
     }
 }
 
 } // namespace blink