Stop treating StreamController as a Stream.

utils/pub/error_group.dart

 // Copyright (c) 2013, 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.
 
 library error_group;
 
 import 'dart:async';
 
 /// An [ErrorGroup] entangles the errors of multiple [Future]s and [Stream]s
 /// with one another. This allows APIs to expose multiple [Future]s and
@@ skipping 230 matching lines @@
         onDone: () {
           _isDone = true;
           _group._signalStreamComplete(this);
           _controller.close();
         });
   }
 
   StreamSubscription listen(void onData(value),
       {void onError(AsyncError error), void onDone(),
        bool unsubscribeOnError}) {
-    return _controller.listen(onData,
+    return _controller.stream.listen(onData,
         onError: onError,
         onDone: onDone,
         unsubscribeOnError: true);
   }
 
   /// Signal that an error from [_group] should be propagated through [this],
   /// unless it's already complete.
   void _signalError(AsyncError e) {
     if (_isDone) return;
     _subscription.cancel();
     // Call these asynchronously to work around issue 7913.
     new Future.immediate(null).then((_) {
       _controller.signalError(e.error, e.stackTrace);
       _controller.close();
     });
   }
 }