function matchSafari() {
  // Apple-based browsers don't support navigator.userAgentData yet, so use
  // navigator.userAgent.
  return util.matchUserAgent('Safari') &&
      !(matchChrome() || matchCoast() || matchOpera() || matchEdgeHtml() ||
        matchEdgeChromium() || matchOperaChromium() || matchFirefox() ||
        isSilk() || util.matchUserAgent('Android'));
}
@return {boolean} Whether the user's browser is Safari.