Roll Observatory packages and add a roll script

packages/watcher/test/directory_watcher/mac_os_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.
+
+@TestOn('mac-os')
+
+import 'package:scheduled_test/scheduled_test.dart';
+import 'package:watcher/src/directory_watcher/mac_os.dart';
+import 'package:watcher/watcher.dart';
+
+import 'shared.dart';
+import '../utils.dart';
+
+void main() {
+  watcherFactory = (dir) => new MacOSDirectoryWatcher(dir);
+
+  setUp(createSandbox);
+
+  sharedTests();
+
+  test('DirectoryWatcher creates a MacOSDirectoryWatcher on Mac OS', () {
+    expect(new DirectoryWatcher('.'),
+        new isInstanceOf<MacOSDirectoryWatcher>());
+  });
+
+  test('does not notify about the watched directory being deleted and '
+      'recreated immediately before watching', () {
+    createDir("dir");
+    writeFile("dir/old.txt");
+    deleteDir("dir");
+    createDir("dir");
+
+    startWatcher(path: "dir");
+    writeFile("dir/newer.txt");
+    expectAddEvent("dir/newer.txt");
+  });
+
+  test('emits events for many nested files moved out then immediately back in',
+      () {
+    withPermutations((i, j, k) =>
+        writeFile("dir/sub/sub-$i/sub-$j/file-$k.txt"));
+
+    startWatcher(path: "dir");
+
+    renameDir("dir/sub", "sub");
+    renameDir("sub", "dir/sub");
+
+    allowEither(() {
+      inAnyOrder(withPermutations((i, j, k) =>
+          isRemoveEvent("dir/sub/sub-$i/sub-$j/file-$k.txt")));
+
+      inAnyOrder(withPermutations((i, j, k) =>
+          isAddEvent("dir/sub/sub-$i/sub-$j/file-$k.txt")));
+    }, () {
+      inAnyOrder(withPermutations((i, j, k) =>
+          isModifyEvent("dir/sub/sub-$i/sub-$j/file-$k.txt")));
+    });
+  });
+}