Revert "Zone support for Futures."

tests/lib/async/run_zoned8_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.
-
-import "package:expect/expect.dart";
-import 'dart:async';
-import 'dart:isolate';
-import 'catch_errors.dart';
-
-main() {
-  // We keep a ReceivePort open until all tests are done. This way the VM will
-  // hang if the callbacks are not invoked and the test will time out.
-  var port = new ReceivePort();
-  var events = [];
-  // Test runZoned with periodic Timers.
-  runZonedExperimental(() {
-    int counter = 0;
-    new Timer.periodic(const Duration(milliseconds: 50), (timer) {
-      if (counter == 1) timer.cancel();
-      counter++;
-      events.add(counter);
-      throw counter;
-    });
-  }, onError: (e) {
-       events.add("error: $e");
-     },
-     onDone: () {
-         Expect.listEquals([
-                           "main exit",
-                           1, "error: 1", 2, "error: 2",
-                           ],
-                           events);
-         port.close();
-       });
-  events.add("main exit");
-}