popup.js

var ctx = document.getElementById("myChart");



chrome.runtime.sendMessage({
    message: "getVisitsStats"
}, function (response) {
    console.log(response);

    var labels = Object.keys(response);
    var data = Object.keys(response).map(function(item){return response[item]});
    showChart(labels.slice(0,6),data.slice(0,6));
});


function showChart(labels, data){
    new Chart(ctx, {
        type: 'bar',
        data: {
            labels: labels,
            datasets: [{
                label: '# of Visits',
                data: data,
                fill:false,
                backgroundColor: [
                    'rgba(255, 99, 132, 0.2)',
                    'rgba(54, 162, 235, 0.2)',
                    'rgba(255, 206, 86, 0.2)',
                    'rgba(75, 192, 192, 0.2)',
                    'rgba(153, 102, 255, 0.2)',
                    'rgba(255, 159, 64, 0.2)'
                ],
                borderColor: [
                    'rgba(255,99,132,1)',
                    'rgba(54, 162, 235, 1)',
                    'rgba(255, 206, 86, 1)',
                    'rgba(75, 192, 192, 1)',
                    'rgba(153, 102, 255, 1)',
                    'rgba(255, 159, 64, 1)'
                ],
                borderWidth: 1
            }]
        },
        options: {
            scales: {
                yAxes: [{
                    ticks: {
                        beginAtZero:true
                    }
                }]
            }
        }
    });
}