Add type to BroadcastSubscriptionWrapper.

sdk/lib/async/stream_impl.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 dart.async;
 
 /** Abstract and private interface for a place to put events. */
 abstract class _EventSink<T> {
   void _add(T data);
   void _addError(Object error, StackTrace stackTrace);
@@ skipping 821 matching lines @@
                                      onError: _controller.addError,
                                      onDone: _controller.close);
     }
     cancelOnError = identical(true, cancelOnError);
     return _controller._subscribe(onData, onError, onDone, cancelOnError);
   }
 
   void _onCancel() {
     bool shutdown = (_controller == null) || _controller.isClosed;
     if (_onCancelHandler != null) {
-      _zone.runUnary(_onCancelHandler, new _BroadcastSubscriptionWrapper(this));
+      _zone.runUnary(
+          _onCancelHandler, new _BroadcastSubscriptionWrapper<T>(this));
     }
     if (shutdown) {
       if (_subscription != null) {
         _subscription.cancel();
         _subscription = null;
       }
     }
   }
 
   void _onListen() {
     if (_onListenHandler != null) {
-      _zone.runUnary(_onListenHandler, new _BroadcastSubscriptionWrapper(this));
+      _zone.runUnary(
+          _onListenHandler, new _BroadcastSubscriptionWrapper<T>(this));
     }
   }
 
   // Methods called from _BroadcastSubscriptionWrapper.
   void _cancelSubscription() {
     if (_subscription == null) return;
     // Called by [_controller] when it has no subscribers left.
     StreamSubscription subscription = _subscription;
     _subscription = null;
     _controller = null;  // Marks the stream as no longer listenable.
@@ skipping 221 matching lines @@
 class _EmptyStream<T> extends Stream<T> {
   const _EmptyStream() : super._internal();
   bool get isBroadcast => true;
   StreamSubscription<T> listen(void onData(T data),
                                {Function onError,
                                 void onDone(),
                                 bool cancelOnError}) {
     return new _DoneStreamSubscription<T>(onDone);
   }
 }