code: function makeTagPolicy(opt_naiveUriRewriter, opt_nmTokenPolicy) {
      return function(tagName, attribs) {
        if (!(html4.ELEMENTS[tagName] & html4.eflags.UNSAFE)) {
          return sanitizeAttribs(
              tagName, attribs, opt_naiveUriRewriter, opt_nmTokenPolicy);
        }
      };
    }
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.