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

Source/platform/network/ProxyServer.cpp

 /*
  * Copyright (C) 2010 Apple 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 16 matching lines @@
 #include "platform/network/ProxyServer.h"
 
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 static void appendProxyServerString(StringBuilder& builder, const ProxyServer& proxyServer)
 {
     switch (proxyServer.type()) {
     case ProxyServer::Direct:
-        builder.append("DIRECT");
+        builder.appendLiteral("DIRECT");
         return;
     case ProxyServer::HTTP:
     case ProxyServer::HTTPS:
-        builder.append("PROXY");
+        builder.appendLiteral("PROXY");
         break;
     case ProxyServer::SOCKS:
-        builder.append("SOCKS");
+        builder.appendLiteral("SOCKS");
         break;
     }
 
     builder.append(' ');
 
     ASSERT(!proxyServer.hostName().isNull());
     builder.append(proxyServer.hostName());
 
     builder.append(':');
     ASSERT(proxyServer.port() != -1);
     builder.appendNumber(proxyServer.port());
 }
 
 String toString(const Vector<ProxyServer>& proxyServers)
 {
     if (proxyServers.isEmpty())
         return "DIRECT";
 
     StringBuilder stringBuilder;
     for (size_t i = 0; i < proxyServers.size(); ++i) {
         if (i)
-            stringBuilder.append("; ");
+            stringBuilder.appendLiteral("; ");
 
         appendProxyServerString(stringBuilder, proxyServers[i]);
     }
 
     return stringBuilder.toString();
 }
 
 
 } // namespace blink