Let StreamSubscription.cancel return a Future.

tests/lib/async/stream_state_test.dart

Index: tests/lib/async/stream_state_test.dart
diff --git a/tests/lib/async/stream_state_test.dart b/tests/lib/async/stream_state_test.dart
index f64d720091e3cd16a26ab268b9feb7d136aaaf07..a7c3ab0152d981a42277f6834ce51160383146eb 100644
--- a/tests/lib/async/stream_state_test.dart
+++ b/tests/lib/async/stream_state_test.dart
@@ -74,12 +74,21 @@ mainTest({bool sync, bool asBroadcast}) {
   test("$p-sub-data-unsubonerror", () {
     var t = asBroadcast ? new StreamProtocolTest.asBroadcast(sync: sync)
                         : new StreamProtocolTest(sync: sync);
-    t..expectListen()
-     ..expectBroadcastListenOpt()
-     ..expectData(42)
-     ..expectError("bad")
-     ..expectBroadcastCancelOpt()
-     ..expectCancel(t.terminate);
+    if (asBroadcast) {
+      t..expectListen()
+       ..expectBroadcastListenOpt()

[floitsch, 2013/10/12 18:53:57]

You should not need to use "Opt".
This is in the "asBroadcast" branch, so this listen should happen
unconditionally. Just remove the "Opt".

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectData(42)
+       ..expectError("bad")
+       ..expectBroadcastCancelOpt()

[floitsch, 2013/10/12 18:53:57]

ditto.

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectCancel(t.terminate);
+    } else {
+      t..expectListen()
+       ..expectBroadcastListenOpt()

[floitsch, 2013/10/12 18:53:57]

Remove, since we are in the non-broadcast branch.

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectData(42)
+       ..expectCancel()
+       ..expectBroadcastCancelOpt()

[floitsch, 2013/10/12 18:53:57]

ditto.

[Anders Johnsen, 2013/10/16 11:52:21]

Done.

+       ..expectError("bad", t.terminate);
+    }
     t..listen(cancelOnError: true)
      ..add(42)
      ..error("bad")