Remove deprecated string features.

tests/standalone/io/http_server_early_client_close_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import "dart:async";
 import "dart:io";
 import "dart:isolate";
 
 void sendData(List<int> data, int port) {
   Socket socket = new Socket("127.0.0.1", port);
@@ skipping 30 matching lines @@
       Expect.isFalse(calledOnError);
       Expect.equals(exception, error.message);
       Expect.equals(expectRequest, calledOnRequest);
       calledOnError = true;
       port.close();
       c.complete(null);
     };
 
     List<int> d;
     if (data is List<int>) d = data;
-    if (data is String) d = data.charCodes;
+    if (data is String) d = data.codeUnits;
     if (d == null) Expect.fail("Invalid data");
     sendData(d, server.port);
 
     return c.future;
   }
 
   final data;
   final String exception;
   final bool expectRequest;
 }
@@ skipping 40 matching lines @@
   server.defaultRequestHandler = (request, response) {
     String name = new Options().script;
     new File(name).openInputStream().pipe(response.outputStream);
   };
 
   var count = 0;
   var makeRequest;
   makeRequest = () {
     Socket socket = new Socket("127.0.0.1", server.port);
     socket.onConnect = () {
-      var data = "GET / HTTP/1.1\r\nContent-Length: 0\r\n\r\n".charCodes;
+      var data = "GET / HTTP/1.1\r\nContent-Length: 0\r\n\r\n".codeUnits;
       socket.writeList(data, 0, data.length);
       socket.close();
       if (++count < 10) {
         makeRequest();
       } else {
         server.close();
       }
     };
   };
 
   makeRequest();
 }
 
 void main() {
   testEarlyClose1();
   testEarlyClose2();
 }