gistfile1.js

function getPerfStats() {
    var timing = window.performance.timing;
    return {
        dns: timing.domainLookupEnd - timing.domainLookupStart,
        connect: timing.connectEnd - timing.connectStart,
        ttfb: timing.responseStart - timing.connectEnd,
        basePage: timing.responseEnd - timing.responseStart,
        frontEnd: timing.loadEventStart - timing.responseEnd
    };
}

window.onload = function() {
    var stats = getPerfStats();
    console.log('stats', stats);
}