Make new StreamController be async by default.

tests/lib/async/stream_state_nonzero_timer_test.dart

 // Copyright (c) 2013, 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.
 
 // Test the event/callback protocol of the stream implementations.
 // Uses a non-zero timer so it fails on d8.
 
 library stream_state_nonzero_timer_test;
 
 import "dart:async";
 import "../../../pkg/unittest/lib/unittest.dart";
 import "stream_state_helper.dart";
 
 const ms5 = const Duration(milliseconds: 5);
 
 main() {
   mainTest(false);
   // TODO(floitsch): reenable?
   // mainTest(true);
 }
 
 mainTest(bool broadcast) {
   var p = broadcast ? "BC" : "SC";
 
   test("$p-sub-data/pause/resume/pause/resume-done", () {
-    var t = new StreamProtocolTest(broadcast);
-    t..expectSubscription()
+    var t = new StreamProtocolTest(broadcast: broadcast);
+    t..expectListen()
      ..expectData(42, () {
          t.pause();
        })
      ..expectPause(() { t.resume(); })
      ..expectResume(() { t.pause(); })
      ..expectPause(() { t.resume(); })
      ..expectResume(() { t.close(); })
      ..expectDone()
      ..expectCancel();
-    t..subscribe()..add(42);
+    t..listen()..add(42);
   });
 
   test("$p-sub-data/pause-done", () {
-    var t = new StreamProtocolTest(broadcast);
-    t..expectSubscription()
+    var t = new StreamProtocolTest(broadcast: broadcast);
+    t..expectListen()
      ..expectData(42, () {
          t.pause(new Future.delayed(ms5, () => null));
        })
      ..expectPause()
      ..expectDone()
      ..expectCancel();
      // We are calling "close" while the controller is actually paused,
      // and it will stay paused until the pending events are sent.
-    t..subscribe()..add(42)..close();
+    t..listen()..add(42)..close();
   });
 
   test("$p-sub-data/pause-resume/done", () {
-    var t = new StreamProtocolTest(broadcast);
-    t..expectSubscription()
+    var t = new StreamProtocolTest(broadcast: broadcast);
+    t..expectListen()
      ..expectData(42, () {
          t.pause(new Future.delayed(ms5, () => null));
        })
      ..expectPause()
      ..expectResume(t.close)
      ..expectDone()
      ..expectCancel();
-    t..subscribe()..add(42);
+    t..listen()..add(42);
   });
 
   test("$p-sub-data/data+pause-data-resume-done", () {
-    var t = new StreamProtocolTest(broadcast);
-    t..expectSubscription()
+    var t = new StreamProtocolTest(broadcast: broadcast);
+    t..expectListen()
      ..expectData(42, () {
          t.add(43);
          t.pause(new Future.delayed(ms5, () => null));
          // Should now be paused until the future finishes.
          // After that, the controller stays paused until the pending queue
          // is empty.
        })
      ..expectPause()
      ..expectData(43)
      ..expectResume(t.close)
      ..expectDone()
      ..expectCancel();
-    t..subscribe()..add(42);
+    t..listen()..add(42);
   });
-return;
+
   test("$p-pause-during-callback", () {
-    var t = new StreamProtocolTest(broadcast);
-    t..expectSubscription()
+    var t = new StreamProtocolTest(broadcast: broadcast);
+    t..expectListen()
      ..expectData(42, () {
        t.pause();
      })
      ..expectPause(() {
        t.resume();
      })
      ..expectResume(() {
        t.pause();
        t.resume();
        t.close();
      })
      ..expectDone()
      ..expectCancel();
-    t..subscribe()
+    t..listen()
      ..add(42);
   });
 }