Mac no longer fire bogus events. Fix Mac watcher.

This is a re-apply of r37162.

BUG=
R=nweiz@google.com

Review URL: https://codereview.chromium.org//621813002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@41220 260f80e4-7a28-3924-810f-c04153c831b5
3 files changed
tree: 7db6c3785ae490d9a3aae9ae0fdb8dba63436578
  1. example/
  2. lib/
  3. test/
  4. CHANGELOG.md
  5. LICENSE
  6. pubspec.yaml
  7. README.md
README.md

A file system watcher.

It monitors changes to contents of directories and sends notifications when files have been added, removed, or modified.