Fix some analyzer warnings and hints in pkg/watcher.

R=rnystrom@google.com
BUG=

Review URL: https://codereview.chromium.org//69013003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/watcher@30172 260f80e4-7a28-3924-810f-c04153c831b5
8 files changed
tree: c3c5e89f81006bef0095f6b2f0a92d045ff4540c
  1. example/
  2. lib/
  3. test/
  4. pubspec.yaml
  5. README.md
README.md

A file watcher. It monitors (currently by polling) for changes to contents of directories and notifies you when files have been added, removed, or modified.