async _markRequestedRedirects(options, redirectChain, response) {
    if (!options.skipRequestedRedirect) return;
    await Promise.all(map(redirectChain, async request => {
      await this._markRequested(extend({}, options, { url: request.url }));
    }));
    await this._markRequested(extend({}, options, { url: response.url }));
  }
@param {!Object} options
@param {!Array<!Object>} redirectChain
@param {!Object} response
@return {!Promise}
@private