Update documentation for "close".

sdk/lib/async/broadcast_stream_controller.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;
 
 class _BroadcastStream<T> extends _ControllerStream<T> {
   _BroadcastStream(_StreamControllerLifecycle controller) : super(controller);
 
   bool get isBroadcast => true;
@@ skipping 162 matching lines @@
     _BroadcastSubscriptionLink previous = subscription._previous;
     _BroadcastSubscriptionLink next = subscription._next;
     previous._next = next;
     next._previous = previous;
     subscription._next = subscription._previous = subscription;
   }
 
   // _StreamControllerLifecycle interface.
 
   StreamSubscription<T> _subscribe(bool cancelOnError) {
-    if (isClosed) {
-      throw new StateError("Subscribing to closed stream");
-    }
     StreamSubscription subscription =
         new _BroadcastSubscription<T>(this, cancelOnError);
+    if (isClosed) {
+      subscription._addPending(const _DelayedDone());
+      return subscription;
+    }
     _addListener(subscription);
     if (identical(_next, _previous)) {
       // Only one listener, so it must be the first listener.
       _runGuarded(_onListen);
     }
     return subscription;
   }
 
   Future _recordCancel(_BroadcastSubscription<T> subscription) {
     // If already removed by the stream, don't remove it again.
@@ skipping 108 matching lines @@
         link = subscription._next;
       }
     }
     _state &= ~_STATE_FIRING;
 
     if (_isEmpty) {
       _callOnCancel();
     }
   }
 
-  void _callOnCancel() {
+  Future _callOnCancel() {

[Anders Johnsen, 2014/06/02 08:22:50]

I see no return statements?

[Lasse Reichstein Nielsen, 2014/06/02 09:48:25]

And I don't remember making this change. Odd.

     assert(_isEmpty);
     if (isClosed && _doneFuture._mayComplete) {
       // When closed, _doneFuture is not null.
       _doneFuture._asyncComplete(null);
     }
     _runGuarded(_onCancel);
   }
 }
 
 class _SyncBroadcastStreamController<T> extends _BroadcastStreamController<T> {
@@ skipping 161 matching lines @@
     _pauseCount++;
   }
   void resume() { _resume(null); }
   void _resume(_) {
     if (_pauseCount > 0) _pauseCount--;
   }
   Future cancel() { return new _Future.immediate(null); }
   bool get isPaused => _pauseCount > 0;
   Future asFuture([Object value]) => new _Future();
 }