google_text_measurement.js

function(a) {
    if (!a) return 0;
    var b = s_ed("div");
    b.style.position = "absolute";
    b.style.whiteSpace = "pre";
    b.style.font = "16px arial,sans-serif";
    a = s_OH(a);
    s_Rc(b, a);
    document.body.appendChild(b);
    a = Math.round(b.offsetWidth);
    document.body.removeChild(b);
    return a
}