Merge IO v2 branch to bleeding edge

sdk/lib/async/stream_impl.dart

Index: sdk/lib/async/stream_impl.dart
diff --git a/sdk/lib/async/stream_impl.dart b/sdk/lib/async/stream_impl.dart
index bbfc98ebb90661fd96348873c1ae0f6a34ced1ae..7d59cc7ed7420d3f95387ec579b42d3242ccd899 100644
--- a/sdk/lib/async/stream_impl.dart
+++ b/sdk/lib/async/stream_impl.dart
@@ -123,7 +123,7 @@ abstract class _StreamImpl<T> extends Stream<T> {
    * should be the last message sent.
    */
   void _close() {
-    if (_isClosed) throw new StateError("Sending on closed stream");
+    if (_isClosed) return;

[Mads Ager (google), 2013/02/21 10:39:02]

We should land this file on bleeding_edge. It is a general change to the async
library that is independent of dart:io v2.

[Søren Gjesse, 2013/02/21 11:44:25]

Anders did.

     _state |= _STREAM_CLOSED;
     if (!_canFireEvent) {
       // You can't enqueue an event after the Done, so make it const.
@@ -310,6 +310,8 @@ abstract class _StreamImpl<T> extends Stream<T> {
    *
    * If an event is currently firing, the cancel is delayed
    * until after the subscribers have received the event.
+   *
+   * This will also close the stream.
    */
   void _cancel(_StreamSubscriptionImpl subscriber);