Add synchronous directory listing to dart:io Directory.

tests/standalone/io/directory_error_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.
 //
 // Dart test program for testing error handling in directory I/O.
 
 import "dart:io";
 import "dart:isolate";
 
 Directory tempDir() {
@@ skipping 121 matching lines @@
   } else if (Platform.operatingSystem == "windows") {
     Expect.equals(3, e.osError.errorCode);
   }
 
   return true;
 }
 
 
 void testListNonExistent(Directory temp, Function done) {
   Directory nonExistent = new Directory("${temp.path}/nonExistent");
+  Expect.throws(() => nonExistent.listSync(), (e) => e is DirectoryIOException);
   var lister = nonExistent.list();
   lister.onError = (e) {
     checkListNonExistentFileException(e);
     done();
   };
 }
 
 
 void testRenameNonExistent(Directory temp, Function done) {
   Directory nonExistent = new Directory("${temp.path}/nonExistent");
@@ skipping 64 matching lines @@
 main() {
   runTest(testCreateInNonExistent);
   runTest(testCreateTempInNonExistent);
   runTest(testDeleteNonExistent);
   runTest(testDeleteRecursivelyNonExistent);
   runTest(testListNonExistent);
   runTest(testRenameNonExistent);
   runTest(testRenameFileAsDirectory);
   runTest(testRenameOverwriteFile);
 }