common/fs/deep-watch.js
function notify (path) {
  var now = Date.now()
  if ((now > okToNotifyAfter) && !ignoreFile.test(path)) {
    process.send(path)
    okToNotifyAfter = now + notifyInterval
    sortList()
  }
}
function notify (path) {
  var now = Date.now()
  if ((now > okToNotifyAfter) && !ignoreFile.test(path)) {
    process.send(path)
    okToNotifyAfter = now + notifyInterval
    sortList()
  }
}
Notify the master process that something changed.