code: function makeTagPolicy(
      opt_naiveUriRewriter, opt_nmTokenPolicy, opt_logger) {
      return function(tagName, attribs) {
        if (!(html4.ELEMENTS[tagName] & html4.eflags['UNSAFE'])) {
          return {
            'attribs': sanitizeAttribs(tagName, attribs,
              opt_naiveUriRewriter, opt_nmTokenPolicy, opt_logger)
          };
        } else {
          if (opt_logger) {
            log(opt_logger, tagName, undefined, undefined, undefined);
          }
        }
      };
    }
docs: Creates a tag policy that omits all tags marked UNSAFE in html4-defs.js
  and applies the default attribute sanitizer with the supplied policy for
  URI attributes and NMTOKEN attributes.
  @param {?function(?string): ?string} opt_naiveUriRewriter A transform to
  apply to URI attributes.  If not given, URI attributes are deleted.
  @param {function(?string): ?string} opt_nmTokenPolicy A transform to apply
  to attributes containing HTML names, element IDs, and space-separated
  lists of classes.  If not given, such attributes are left unchanged.
  @return {function(string, Array.<?string>)} A tagPolicy suitable for
  passing to html.sanitize.