Wrap Directory.watch on linux for the watcher package.

pkg/watcher/test/no_subscription/polling_test.dart

Index: pkg/watcher/test/no_subscription/polling_test.dart
diff --git a/pkg/watcher/test/no_subscription/polling_test.dart b/pkg/watcher/test/no_subscription/polling_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..fa4f0cbe268d8b41c43c93ea36c87fb8acf76cad
--- /dev/null
+++ b/pkg/watcher/test/no_subscription/polling_test.dart
@@ -0,0 +1,19 @@
+// 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 'package:scheduled_test/scheduled_test.dart';
+import 'package:watcher/watcher.dart';
+
+import 'shared.dart';
+import '../utils.dart';
+
+main() {
+  initConfig();
+
+  watcherFactory = (dir) => new PollingDirectoryWatcher(dir);
+
+  setUp(createSandbox);
+
+  sharedTests();
+}