Remove deprecated parts of dart:async.

tests/lib/async/intercept_schedule_microtask6_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:async_helper/async_helper.dart';
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'catch_errors.dart';
 
 class A {
@@ skipping 16 matching lines @@
   events.add("async handler done");
 }
 
 onErrorHandler(e) {
   events.add("error: $e");
 }
 
 main() {
   asyncStart();
 
-  // Test that runZonedExperimental works when async, error and done are used.
+  // Test that runZonedScheduleMicrotask works when async, error and done
+  // are used.
   var result = runZonedScheduleMicrotask(
       body,
       onScheduleMicrotask: onAsyncHandler,
       onError: onErrorHandler);
   events.add("after");
   Timer.run(() {
     Expect.listEquals(
         ["body entry",
          "async handler", "async handler done",
          "after",
          "run async body",
          "error: foo"],
         events);
     asyncEnd();
  });
 }