Arrows in Leaflet

arrows.js

var arrowPolyline = L.Polyline.extend({
    addArrows: function(){
        var points = this.getLatLngs()
        for (var p = 0; p +1 < points.length; p++){ 
            var diffLat = points[p+1]["lat"] - points[p]["lat"]
            var diffLng = points[p+1]["lng"] - points[p]["lng"]
            var center = [points[p]["lat"] + diffLat/2,points[p]["lng"] + diffLng/2]
            var angle = 360 - (Math.atan2(diffLat, diffLng)*57.295779513082)
            var arrowM = new L.marker(center,{
               icon: new L.divIcon({ 
                   className : "arrowIcon",
                   iconSize: new L.Point(30,30), 
                   iconAnchor: new L.Point(15,15), 
                   html : "<div style = 'font-size: 20px; -webkit-transform: rotate("+ angle +"deg)'>&#10152;</div>"
               })
            }).addTo(map);
        }
    }
})