Make IOSink implement StringSink

tests/standalone/io/socket_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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import "dart:async";
@@ skipping 95 matching lines @@
   });
 }
 
 void testConnectConsumerWriteClose() {
   // Connect socket write some data immediate close the consumer
   // without listening on the stream.
   ReceivePort port = new ReceivePort();
   ServerSocket.bind().then((server) {
     server.listen((_) { });
     Socket.connect("127.0.0.1", server.port).then((socket) {
-      socket.add([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
+      socket.writeBytes([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
       socket.close();
       socket.done.then((_) {
         socket.destroy();
         server.close();
         port.close();
       });
     });
   });
 }
 
@@ skipping 21 matching lines @@
 }
 
 void testConnectStreamDataClose(bool useDestroy) {
   // Connect socket and listen on the stream. The server sends data
   // and then closes so both data and a done event is received.
   List<int> sendData = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
   ReceivePort port = new ReceivePort();
   ServerSocket.bind().then((server) {
     server.listen(
         (client) {
-          client.add(sendData);
+          client.writeBytes(sendData);
           if (useDestroy) {
             client.destroy();
           } else {
             client.close();
           }
           client.done.then((_) { if (!useDestroy) { client.destroy(); } });
         });
     Socket.connect("127.0.0.1", server.port).then((socket) {
         List<int> data = [];
         bool onDoneCalled = false;
         socket.listen(data.addAll,
                       onDone: () {
                         Expect.isFalse(onDoneCalled);
                         onDoneCalled = true;
                         if (!useDestroy) Expect.listEquals(sendData, data);
-                        socket.add([0]);
+                        socket.writeBytes([0]);
                         socket.close();
                         server.close();
                         port.close();
                       });
     });
   });
 }
 
 void testConnectStreamDataCloseCancel(bool useDestroy) {
   List<int> sendData = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
   ReceivePort port = new ReceivePort();
   ServerSocket.bind().then((server) {
     server.listen(
         (client) {
-          client.add(sendData);
+          client.writeBytes(sendData);
           if (useDestroy) {
             client.destroy();
           } else {
             client.close();
           }
           client.done
               .then((_) {
                 if (!useDestroy) client.destroy();
               })
               .catchError((e) { /* can happen with short writes */ });
@@ skipping 21 matching lines @@
   testConnectNoDestroy();
   testConnectImmediateDestroy();
   testConnectConsumerClose();
   testConnectConsumerWriteClose();
   testConnectStreamClose();
   testConnectStreamDataClose(true);
   testConnectStreamDataClose(false);
   testConnectStreamDataCloseCancel(true);
   testConnectStreamDataCloseCancel(false);
 }