Change dart:io to use Future for one-shot operations.

tests/standalone/io/directory_invalid_arguments_test.dart

 // Copyright (c) 2012, 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("dart:io");
 
 class DirectoryInvalidArgumentsTest {
   static void testFailingList(Directory d, var recursive) {
     int errors = 0;
-    d.onError = (error) {
+    var lister = d.list(recursive);
+    lister.onError = (error) {
       errors += 1;
     };
-    d.onDone = (completed) {
+    lister.onDone = (completed) {
       Expect.equals(1, errors);
       Expect.isFalse(completed);
     };
     Expect.equals(0, errors);
-    d.list(recursive);
   }
 
   static void testInvalidArguments() {
     Directory d = new Directory(12);
     try {
       d.existsSync();
       Expect.fail("No exception thrown");
     } catch (var e) {
       Expect.isTrue(e is IllegalArgumentException);
     }
@@ skipping 15 matching lines @@
   }
 
   static void testMain() {
     testInvalidArguments();
   }
 }
 
 main() {
   DirectoryInvalidArgumentsTest.testMain();
 }