Fix list output stream

runtime/bin/list_stream.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.
 
 class ListInputStream extends _BaseDataInputStream implements InputStream {
   ListInputStream(List<int> this._buffer) {
     _streamMarkedClosed = true;
   }
 
   int available() => _buffer.length - _offset;
@@ skipping 53 matching lines @@
 class ListOutputStream implements OutputStream {
   ListOutputStream() : _bufferList = new _BufferList();
 
   bool write(List<int> buffer, [bool copyBuffer = false]) {
     if (_streamMarkedClosed) throw new StreamException.streamClosed();
     if (copyBuffer) {
       _bufferList.add(buffer.getRange(0, buffer.length));
     } else {
       _bufferList.add(buffer);
     }
+    return true;
   }
 
   bool writeFrom(List<int> buffer, [int offset = 0, int len]) {
     if (_streamMarkedClosed) throw new StreamException.streamClosed();
     _bufferList.add(
         buffer.getRange(offset, (len == null) ? buffer.length - offset : len));
+    return true;
   }
 
   void close() {
     if (_streamMarkedClosed) throw new StreamException.streamClosed();
     _streamMarkedClosed = true;
   }
 
   void destroy() {
     close();
   }
@@ skipping 48 matching lines @@
   }
 
   _BufferList _bufferList;
   bool _streamMarkedClosed = false;
   bool _closeCallbackCalled = false;
   Timer _scheduledNoPendingWriteCallback;
   Timer _scheduledCloseCallback;
   Function _clientNoPendingWriteHandler;
   Function _clientCloseHandler;
 }