Remove public SocketInputStream and SocketOutputStream clases

tests/standalone/io/echo_server_stream_test.dart

Index: tests/standalone/io/echo_server_stream_test.dart
diff --git a/tests/standalone/io/echo_server_stream_test.dart b/tests/standalone/io/echo_server_stream_test.dart
index c30fc95faab2359a1956e92f9ff1f5fe0e1153f4..3368b5cf84846a5f525ffdddef78ba798f287b0c 100644
--- a/tests/standalone/io/echo_server_stream_test.dart
+++ b/tests/standalone/io/echo_server_stream_test.dart
@@ -39,7 +39,7 @@ class EchoServerGame {
 
     void connectHandler() {
 
-      SocketOutputStream stream = _socket.outputStream;
+      OutputStream stream = _socket.outputStream;
 
       void dataSent() {
         InputStream inputStream = _socket.inputStream;
@@ -149,9 +149,8 @@ class EchoServer extends TestingServer {
     int offset = 0;
 
     void dataReceived() {
-      SocketOutputStream outputStream;
       int bytesRead;
-      outputStream = connection.outputStream;
+      OutputStream outputStream = connection.outputStream;
       bytesRead = inputStream.readInto(buffer, offset, MSGSIZE - offset);
       if (bytesRead > 0) {
         offset += bytesRead;