var ctx = document.getElementById("pieChartBrowsers").getContext("2d");

$.getJSON('/stats/ua/browsers', function(browsers_json) {
    var data = {
        datasets: [{
            data: browsers_json.values
        }],
        labels: browsers_json.keys
    };

    var options = {
        'animation.animateRotate': true,
        'circumference': Math.PI * 2
    };

    var myChart = new Chart(ctx, {
        type: 'pie',
        data: data,
        options: options
    });
});