Add 'isDir' to FileSystemEvent.

tests/standalone/io/file_system_watcher_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 "dart:async";
 import "dart:io";
 
 import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
 
 
 void testWatchCreateFile() {
   var dir = Directory.systemTemp.createTempSync('dart_file_system_watcher');
   var file = new File(dir.path + '/file');
 
   var watcher = dir.watch();
 
   asyncStart();
   var sub;
   sub = watcher.listen((event) {
     if (event is FileSystemCreateEvent &&
         event.path.endsWith('file')) {
+      Expect.isFalse(event.isDir);

[Bill Hesse, 2013/10/28 16:30:13]

Will there be a test where isDir is true?  There should be.

[Anders Johnsen, 2013/10/28 16:43:14]

Done.

       asyncEnd();
       sub.cancel();
       dir.deleteSync(recursive: true);
     }
   }, onError: (e) {
     dir.deleteSync(recursive: true);
     throw e;
   });
 
   file.createSync();
@@ skipping 240 matching lines @@
   testWatchCreateFile();
   testWatchModifyFile();
   testWatchMoveFile();
   testWatchDeleteFile();
   testWatchDeleteDir();
   testWatchOnlyModifyFile();
   testMultipleEvents();
   testWatchNonRecursive();
   testWatchNonExisting();
 }