naiveUriRewriter = function(uri, prop) {
    'use strict';
    policyHints.cssProperty = prop;
    var sanitizedUrl = policySanitizeUrl(uri, policyHints);
    if (sanitizedUrl == null) {
      return null;
    }
    return goog.html.uncheckedconversions
        .safeUrlFromStringKnownToSatisfyTypeContract(
            goog.string.Const.from(
                'HtmlSanitizerPolicy created with networkRequestUrlPolicy_ ' +
                'when installing \'* STYLE\' handler.'),
            sanitizedUrl);
  }
Sanitizes a list of CSS declarations.
@param {goog.html.sanitizer.HtmlSanitizerPolicy} policySanitizeUrl
@param {string} attrValue
@param {goog.html.sanitizer.HtmlSanitizerPolicyHints} policyHints
@param {goog.html.sanitizer.HtmlSanitizerPolicyContext} policyContext
@return {?string} sanitizedCss from the policyContext
@private