window.performance.timing

var timing = window.performance.timing,
  metrics = {
      dns: timing.domainLookupEnd - timing.domainLookupStart,
      tcp: timing.connectEnd - timing.connectStart,
      request: timing.responseStart - timing.requestStart,
      response: timing.responseEnd - timing.responseStart,
      paint: timing.domContentLoadedEventEnd - timing.domLoading,
      dom: timing.domComplete - timing.domLoading,
      total: timing.loadEventEnd - timing.navigationStart
  };