code: function(e) {
      goog.log.finest(me.logger, me + ': Tx ' + mode + ' request cause error.');
      // NOTE: we have to call ABORT, instead of ERROR, here.
      // IndexedDB API use COMPLETE or ABORT as promise callbacks.
      // ERROR is just an event.
      completed_event_handler(ydn.db.base.TxEventTypes.ABORT, e);
    }
docs: SQLTransactionErrorCallback
  @param {SQLError} e error.