chrome.runtime.onConnect.addListener(function (port) {
    port.onMessage.addListener(messageHandler);

    // listen to "content-script.js"
    function messageHandler(message) {
        if(message == 'get-screen-id') {
            chrome.desktopCapture.chooseDesktopMedia(['screen', 'window'], port.sender.tab, onUserAction);
        }
    }

    function onUserAction(sourceId) {

        //Access denied
        if(!sourceId || !sourceId.length) {
            return port.postMessage('permission-denie');
        }

        port.postMessage({
            sourceId: sourceId
        });
    }
});