Clean up directory listing interface.

runtime/tests/dart/src/DirectoryTest.dart

 // Copyright (c) 2011, 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.
 //
 // Directory listing test.
 
 class DirectoryTest {
   static void testListing() {
     bool listedSomething = false;
-    Directory directory = new Directory.open(".");
+    Directory directory = new Directory(".");
 
     directory.setDirHandler((dir) {
       listedSomething = true;
     });
 
     directory.setFileHandler((f) {
       listedSomething = true;
     });
 
     directory.setDoneHandler((completed) {
       Expect.isTrue(completed, "directory listing did not complete");
       Expect.isTrue(listedSomething, "empty directory");
-      directory.close();
     });
 
-    directory.setDirErrorHandler((dir) {
-      Expect.fail("error listing directory");
+    directory.setErrorHandler((error) {
+      Expect.fail("error listing directory: $error");
     });
 
     directory.list();
 
     // Listing is asynchronous, so nothing should be listed at this
     // point.
     Expect.isFalse(listedSomething);
   }
 
   static void testMain() {
     testListing();
   }
 }
 
 main() {
   DirectoryTest.testMain();
 }