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

Source/platform/UUID.cpp

 /*
 * Copyright (C) 2010 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 28 matching lines @@
 
 String createCanonicalUUIDString()
 {
     unsigned randomData[4];
     cryptographicallyRandomValues(reinterpret_cast<unsigned char*>(randomData), sizeof(randomData));
 
     // Format as Version 4 UUID.
     StringBuilder builder;
     builder.reserveCapacity(36);
     appendUnsignedAsHexFixedSize(randomData[0], builder, 8, Lowercase);
-    builder.append("-");
+    builder.append('-');
     appendUnsignedAsHexFixedSize(randomData[1] >> 16, builder, 4, Lowercase);
-    builder.append("-4");
+    builder.appendLiteral("-4");
     appendUnsignedAsHexFixedSize(randomData[1] & 0x00000fff, builder, 3, Lowercase);
-    builder.append("-");
+    builder.append('-');
     appendUnsignedAsHexFixedSize((randomData[2] >> 30) | 0x8, builder, 1, Lowercase);
     appendUnsignedAsHexFixedSize((randomData[2] >> 16) & 0x00000fff, builder, 3, Lowercase);
-    builder.append("-");
+    builder.append('-');
     appendUnsignedAsHexFixedSize(randomData[2] & 0x0000ffff, builder, 4, Lowercase);
     appendUnsignedAsHexFixedSize(randomData[3], builder, 8, Lowercase);
     return builder.toString();
 }
 
 }