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

tests/standalone/io/file_output_stream_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.
 // Testing file input stream, VM-only, standalone test.
 
 #import("dart:io");
 #import("dart:isolate");
 
 void testOpenOutputStreamSync() {
-  Directory tempDirectory = new Directory('');
+  Directory tempDirectory = new Directory('').createTempSync();
 
   // Create a port for waiting on the final result of this test.
   ReceivePort done = new ReceivePort();
   done.receive((message, replyTo) {
     tempDirectory.deleteSync();
     done.close();
   });
 
-  tempDirectory.createTempSync();
   String fileName = "${tempDirectory.path}/test";
   File file = new File(fileName);
   file.createSync();
   OutputStream x = file.openOutputStream();
   x.write([65, 66, 67]);
   x.close();
   x.onClosed = () {
     file.deleteSync();
     done.toSendPort().send("done");
   };
 }
 
 
 void testOutputStreamNoPendingWrite() {
-  Directory tempDirectory = new Directory('');
+  var tempDirectory;
 
   // Create a port for waiting on the final result of this test.
   ReceivePort done = new ReceivePort();
   done.receive((message, replyTo) {
-    tempDirectory.deleteRecursively(() {
-      done.close();
-    });
+    tempDirectory.deleteRecursively().then((ignore) => done.close());
   });
 
-  tempDirectory.createTemp(() {
+  new Directory('').createTemp().then((temp) {
+    tempDirectory = temp;
     String fileName = "${tempDirectory.path}/test";
     File file = new File(fileName);
-    file.create(() {
+    file.create().then((ignore) {
       OutputStream stream = file.openOutputStream();
       final total = 100;
       var count = 0;
       stream.onNoPendingWrites = () {
         stream.write([count++]);
         if (count == total) {
           stream.close();
         }
         stream.onClosed = () {
           List buffer = new List<int>(total);
@@ skipping 10 matching lines @@
       };
     });
   });
 }
 
 
 main() {
   testOpenOutputStreamSync();
   testOutputStreamNoPendingWrite();
 }