Change timer delay to 0 to make jsshell happy.

tests/lib/async/stream_iterator_double_cancel_test.dart

 // Copyright (c) 2015, 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.
 
 import "dart:async";
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 
 Stream timedStream(int n) {
   int i = 0;
   StreamController controller;
   tick() {
     if (i >= n) {
       controller.close();
       return;
     }
     controller.add(i);
     i++;
-    new Future.delayed(new Duration(milliseconds: 10), tick);
+    new Future.delayed(new Duration(milliseconds: 0), tick);
   }
   controller = new StreamController(onListen: tick);
   return controller.stream;
 }
 
 void main() {
   asyncStart();
   StreamIterator iterator = new StreamIterator(timedStream(10));
   helper(more) {
     if (!more) {
       // Canceling the already closed iterator should not lead to a crash.
       iterator.cancel();
       asyncEnd();
     } else {
       iterator.moveNext().then(helper);
     }
   }
   iterator.moveNext().then(helper);
 }