Replace broken language/async_star_await_pauses_test

tests/language/async_star_await_pauses_test.dart

-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file

[ahe, 2016/04/08 11:46:15]

The name of this test is odd. I think it should be renamed to
async_await_for_pauses_text.dart as it doesn't use "async*", and tests "await
for", not "await".

 // 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.
 
 import "dart:async";
-import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 
 main() {
-  var sc;
-  var i = 0;
-  void send() {
-    if (i == 5) {
-      sc.close();
-    } else {
-      sc.add(i++);
+  Completer listenEventReceived = new Completer();
+  Completer pauseEventReceived = new Completer();
+  Completer resumeEventReceived = new Completer();
+  StreamController controller = new StreamController(
+      onListen: () => listenEventReceived.complete(),
+      onPause: () => pauseEventReceived.complete(),
+      onResume: () => resumeEventReceived.complete());
+
+  Completer forLoopEntered = new Completer();
+
+  send() async {

[ahe, 2016/04/08 11:46:15]

Since this is a language feature test of "await for", I think it would be best
to avoid using other async/await features. I know this is less convenient.

+    await listenEventReceived.future;
+    controller.add("first");
+    await forLoopEntered.future;
+    var timer = new Timer.periodic(new Duration(milliseconds: 10), (timer) {
+      controller.add("second");
+    });
+    await pauseEventReceived.future;
+    timer.cancel();
+    await resumeEventReceived.future;
+    controller.add("third");
+    controller.close();
+  }
+
+  receive() async {
+    await for (var entry in controller.stream) {
+      if (entry == 'first') {
+        forLoopEntered.complete();
+        await pauseEventReceived.future;
+      }
     }
   }
-  sc = new StreamController(onListen: send, onResume: send);
 
-  f(s) async {
-    var r = 0;
-    await for (var i in s) {
-      r += await new Future.delayed(new Duration(milliseconds: 10), () => i);
-    }
-    return r;
-  }
-
-  asyncStart();
-  f(sc.stream).then((v) {
-    Expect.equals(10, v);
-    asyncEnd();
+  asyncTest(() async {
+    var f = send();
+    await receive();
+    await f;
   });
 }