function watchPath(path, ignored, callback) {
        if (_isRunningOnWindowsXP) {
            callback(FileSystemError.NOT_SUPPORTED);
            return;
        }
        appshell.fs.isNetworkDrive(path, function (err, isNetworkDrive) {
            if (err || isNetworkDrive) {
                if (isNetworkDrive) {
                    callback(FileSystemError.NETWORK_DRIVE_NOT_SUPPORTED);
                } else {
                    callback(FileSystemError.UNKNOWN);
                }
                return;
            }
            _nodeDomain.exec("watchPath", path, ignored)
                .then(callback, callback);
        });
    }
Start providing change notifications for the file or directory at the
given path, calling back asynchronously with a possibly null FileSystemError
string when the initialization is complete. Notifications are provided
using the changeCallback function provided by the initWatchers method.
Note that change notifications are only provided recursively for directories
when the recursiveWatch property of this module is true.

@param {string} path
@param {Array<string>} ignored
@param {function(?string)=} callback