Rename runAsync to scheduleMicrotask.

tests/lib/async/zone_empty_description_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 'package:async_helper/async_helper.dart';
 import 'dart:async';
 
 testForkedZone(Zone forked) {
   var result;
@@ skipping 33 matching lines @@
   Expect.identical(callback, forked.registerCallback(callback));
   Expect.identical(Zone.ROOT, Zone.current);
 
   var callback1 = (x) => 42 + x;
   Expect.identical(callback1, forked.registerUnaryCallback(callback1));
   Expect.identical(Zone.ROOT, Zone.current);
 
   asyncStart();
   bool asyncDidRun = false;
   forked.scheduleMicrotask(() {
-    // The runAsync functions on the Zone don't bind the closures.
+    // The scheduleMicrotask functions on the Zone don't bind the closures.
     Expect.identical(Zone.ROOT, Zone.current);
     asyncDidRun = true;
     asyncEnd();
   });
   Expect.isFalse(asyncDidRun);
   Expect.identical(Zone.ROOT, Zone.current);
 
   asyncStart();
   bool timerDidRun = false;
   forked.createTimer(const Duration(milliseconds: 0), () {
     // The createTimer functions on the Zone don't bind the closures.
     Expect.identical(Zone.ROOT, Zone.current);
     timerDidRun = true;
     asyncEnd();
   });
   Expect.identical(Zone.ROOT, Zone.current);
 }
 
 main() {
   Expect.identical(Zone.ROOT, Zone.current);
   Zone forked = Zone.current.fork();
   Expect.isFalse(identical(Zone.ROOT, forked));
   testForkedZone(forked);
   Zone forkedChild = forked.fork();
   testForkedZone(forkedChild);
 }