code: function unwatchPath(path, ignored, callback) {
          _nodeDomain.exec("unwatchPath", path)
              .then(callback, callback);
      }
docs: Stop providing change notifications for the file or directory at the
  given path, calling back asynchronously with a possibly null FileSystemError
  string when the operation is complete.
  This function needs to mirror the signature of watchPath
  because of FileSystem.prototype._watchOrUnwatchEntry implementation.
  
  @param {string} path
  @param {Array<string>} ignored
  @param {function(?string)=} callback