Added toMultiSubscriber on Stream.

sdk/lib/async/stream.dart

Index: sdk/lib/async/stream.dart
diff --git a/sdk/lib/async/stream.dart b/sdk/lib/async/stream.dart
index 68e2588bbab43e4717b253c5116992817a0e4ed8..2aa611aad9889d3709b62aaec0bf3c1eea0304d0 100644
--- a/sdk/lib/async/stream.dart
+++ b/sdk/lib/async/stream.dart
@@ -25,6 +25,18 @@ abstract class Stream<T> {
   }
 
   /**
+   * Returns a multi-subscription stream that produces the same events.

[floitsch, 2013/01/08 14:06:00]

same events as [this].

[Lasse Reichstein Nielsen, 2013/01/09 15:19:17]

Done.

+   *
+   * If this stream is single-subscription, the new multi-subscription

[floitsch, 2013/01/08 14:06:00]

As discussed: we want to be more specific on the behavior of the returned
stream.

[Lasse Reichstein Nielsen, 2013/01/09 15:19:17]

Done.

+   * stream gets its data by subscribing to this stream which must not already
+   * have a subscriber, and which can't get another subscriber at a later time.
+   *
+   * If this stream is already multi-subscriber, there is no difference between
+   * this stream and the returned stream. They may even be the same object.
+   */
+  Stream<T> toMultiSubscriber();

[floitsch, 2013/01/08 14:06:00]

asMultiSubscriptionStream()

[Lasse Reichstein Nielsen, 2013/01/09 15:19:17]

Very, very long. 
Doesn't match new StreamController.singleSubscription()

But done.

+
+  /**
    * Stream that outputs events from the [sources] in cyclic order.
    *
    * The merged streams are paused and resumed in order to ensure the proper