code: function getProxyListString(proxies) {
        // Older versions of Chrome would set these values as strings, whereas
        // newer
        // logs use arrays.
        // TODO(eroman): This behavior changed in M27. Support for older logs can
        //               safely be removed circa M29.
        if (Array.isArray(proxies)) {
          const listString = proxies.join(', ');
          if (proxies.length > 1) {
            return '[' + listString + ']';
          }
          return listString;
        }
        return proxies;
      }
docs: TODO(eroman): if |config| has unexpected properties, print it as JSON rather than hide them.