Remove public SocketInputStream and SocketOutputStream clases

tests/standalone/io/stream_pipe_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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 #import("dart:io");
@@ skipping 60 matching lines @@
     _sendPort = spawnFunction(startPipeServer);
     initialize();
   }
 
   void runTest() {
 
     void connectHandler() {
       String srcFileName =
           getDataFilename("tests/standalone/io/readline_test1.dat");
 
-      SocketOutputStream socketOutput = _socket.outputStream;
+      OutputStream socketOutput = _socket.outputStream;
       InputStream fileInput = new File(srcFileName).openInputStream();
 
       fileInput.onClosed = () {
-        SocketInputStream socketInput = _socket.inputStream;
+        InputStream socketInput = _socket.inputStream;
         var tempDir = new Directory('').createTempSync();
         var dstFileName = tempDir.path.concat("/readline_test1.dat");
         var dstFile = new File(dstFileName);
         dstFile.createSync();
         var fileOutput = dstFile.openOutputStream();
 
         socketInput.onClosed = () {
           // Check that the resulting file is equal to the initial
           // file.
           fileOutput.onClosed = () {
@@ skipping 189 matching lines @@
   srcStream.pipe(dstStream, close: false);
 }
 
 
 main() {
   testFileToFilePipe1();
   testFileToFilePipe2();
   testFileToFilePipe3();
   PipeServerGame echoServerGame = new PipeServerGame.start();
 }