1. @DomName('IDBObjectStore.count')
Future<int> count([key_OR_range ])

Source 

@DomName('IDBObjectStore.count')
Future<int> count([key_OR_range]) {
  try {
    var request = _count(key_OR_range);
    return _completeRequest(request);
  } catch (e, stacktrace) {
    return new Future.error(e, stacktrace);
  }
}