map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: 43.693226, lng: -79.383184},
    styles: [
        {
            featureType: 'transit',
            elementType: 'labels.icon',
            stylers: [{visibility: 'off'}]
        },
        {
            featureType: 'poi',
            elementType: 'labels',
            stylers: [{visibility: 'off'}]
        },
    ]
});

var poiToggleOn = false;
document.getElementById('poiToggle').addEventListener('click', function() {
    if (poiToggleOn === false) {
        poiToggleOn = true;
        map.setOptions({styles: [
            {
                featureType: 'poi',
                elementType: 'labels',
                stylers: [{visibility: 'off'}]
            }
        ]})
    } else {
        poiToggleOn = false;
        map.setOptions({styles: [
            {
                featureType: 'poi',
                elementType: 'labels',
                stylers: [{visibility: 'on'}]
            }
        ]})
    }
});