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

Source/platform/text/PlatformLocale.cpp

 /*
  * Copyright (C) 2011,2012 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 64 matching lines @@
     return DateTimeFormat::parse(formatString, *this);
 }
 
 String DateTimeStringBuilder::zeroPadString(const String& string, size_t width)
 {
     if (string.length() >= width)
         return string;
     StringBuilder zeroPaddedStringBuilder;
     zeroPaddedStringBuilder.reserveCapacity(width);
     for (size_t i = string.length(); i < width; ++i)
-        zeroPaddedStringBuilder.append("0");
+        zeroPaddedStringBuilder.append('0');
     zeroPaddedStringBuilder.append(string);
     return zeroPaddedStringBuilder.toString();
 }
 
 void DateTimeStringBuilder::appendNumber(int number, size_t width)
 {
     String zeroPaddedNumberString = zeroPadString(String::number(number), width);
     m_builder.append(m_localizer.convertToLocalizedNumber(zeroPaddedNumberString));
 }
 
@@ skipping 261 matching lines @@
 
     bool isNegative;
     unsigned startIndex;
     unsigned endIndex;
     if (!detectSignAndGetDigitRange(input, isNegative, startIndex, endIndex))
         return input;
 
     StringBuilder builder;
     builder.reserveCapacity(input.length());
     if (isNegative)
-        builder.append("-");
+        builder.append('-');
     for (unsigned i = startIndex; i < endIndex;) {
         unsigned symbolIndex = matchedDecimalSymbolIndex(input, i);
         if (symbolIndex >= DecimalSymbolsSize)
             return input;
         if (symbolIndex == DecimalSeparatorIndex)
             builder.append('.');
         else if (symbolIndex == GroupSeparatorIndex)
             return input;
         else
             builder.append(static_cast<UChar>('0' + symbolIndex));
@@ skipping 33 matching lines @@
         builder.build(formatType == FormatTypeShort ? dateTimeFormatWithoutSeconds() : dateTimeFormatWithSeconds());
         break;
     case DateComponents::Invalid:
         ASSERT_NOT_REACHED();
         break;
     }
     return builder.toString();
 }
 
 }