Pass proper number of arguments.

tools/dom/src/native_DOMImplementation.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.
 
 part of html;
 
 class _Utils {
   static double dateTimeToDouble(DateTime dateTime) =>
       dateTime.millisecondsSinceEpoch.toDouble();
   static DateTime doubleToDateTime(double dateTime) {
@@ skipping 166 matching lines @@
     } else if (cmd == _PRINT) {
       final message = msg[1];
       // TODO(antonm): we need somehow identify those isolates.
       print('[From isolate] $message');
     }
   });
 }
 
 final _printClosure = window.console.log;
 final _pureIsolatePrintClosure = (s) {
-  _sendToHelperIsolate([_PRINT, s]);
+  _sendToHelperIsolate([_PRINT, s], null);
 };
 
 final _forwardingPrintClosure = _Utils.forwardingPrint;