Fix list output stream

tests/standalone/src/ListInputStreamTest.dart

 // Copyright (c) 2011, 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.
 
 void testEmptyListInputStream() {
   InputStream stream = new ListInputStream([]);
   ReceivePort donePort = new ReceivePort();
 
   void onData() {
     throw "No data expected";
@@ skipping 154 matching lines @@
   stream.closeHandler = onClose;
 
   donePort.receive((x,y) => donePort.close());
 }
 
 main() {
   testEmptyListInputStream();
   testEmptyDynamicListInputStream();
   testListInputStream1();
   testListInputStream2();
-  //testListInputStreamPipe1();
-  //testListInputStreamPipe2();
+  testListInputStreamPipe1();
+  testListInputStreamPipe2();
   testDynamicListInputStream1();
 }