Use Uint8List instead of String when sending messages.

tests/standalone/io/web_socket_test.dart

 // Copyright (c) 2012, 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:io");
 
 void testRequestResponseClientCloses(
     int totalConnections, int closeStatus, String closeReason) {
   HttpServer server = new HttpServer();
@@ skipping 92 matching lines @@
 
 
 void testMessageLength(int messageLength) {
   HttpServer server = new HttpServer();
   HttpClient client = new HttpClient();
 
   server.listen("127.0.0.1", 0, 1);
 
   // Create a web socket handler and set is as the HTTP server default
   // handler.
-  String originalMessage = "";
-  for (int i = 0; i < messageLength; i++) originalMessage += "${i % 10}";
+  Uint8List originalMessage = new Uint8List(messageLength);
   WebSocketHandler wsHandler = new WebSocketHandler();
   wsHandler.onOpen = (WebSocketConnection conn) {
     conn.onMessage = (Object message) {
-      Expect.equals(originalMessage, message);
+      Expect.listEquals(originalMessage, message);
       conn.send(message);
     };
     conn.onClosed = (status, reason) {
     };
   };
   server.defaultRequestHandler = wsHandler.onRequest;
 
   HttpClientConnection conn = client.get("127.0.0.1", server.port, "/");
   WebSocketClientConnection wsconn = new WebSocketClientConnection(conn);
   wsconn.onMessage = (message) {
-    Expect.equals(originalMessage, message);
+    Expect.listEquals(originalMessage, message);
     wsconn.close();
   };
   wsconn.onClosed = (status, reason) {
     server.close();
   };
   wsconn.onOpen = () {
     wsconn.send(originalMessage);
   };
 }
 
@@ skipping 184 matching lines @@
   testMessageLength(126);
   testMessageLength(127);
   testMessageLength(65535);
   testMessageLength(65536);
   testNoUpgrade();
   testUsePOST();
   testHashCode(2);
 
   testW3CInterface(2, 3002, "Got tired");
 }