function sanitizeWithPolicy(inputHtml, tagPolicy) {
    var outputArray = [];
    makeHtmlSanitizer(tagPolicy)(inputHtml, outputArray);
    return outputArray.join('');
  }
Sanitizes HTML tags and attributes according to a given policy.
@param {string} inputHtml The HTML to sanitize.
@param {function(string, Array.<?string>)} tagPolicy A function that
    decides which tags to accept and sanitizes their attributes (see
    makeHtmlSanitizer above for details).
@return {string} The sanitized HTML.