How do I overlay a polyline with markers on this google map in WP?

I already have the Google map set up, and it’s set to create markers from listings in my WP theme that contain either street info or lat, long info. This works fine in the code below. However, I can’t figure out how to add a polyline path to this map as well. I’m a noob on JS, but as far as I understood… as long as you use the ‘setMap’ method, this should work. Here’s what I have so far, how/where should I add in the polyline to this, so that I can add something like this to the page: http://www.w3schools.com/googleAPI/tryit.asp?filename=tryhtml_map_overlays_polyline? Thank you very much to anyone that can help!

var estateMapping = (function () {
    var self = {},
        marker_list = [],
        open_info_window = null,
        x_center_offset = 0, // x,y offset in px when map gets built with marker bounds
        y_center_offset = -100,
        x_info_offset = 0, // x,y offset in px when map pans to marker -- to accomodate infoBubble
        y_info_offset = -100;

    function build_marker(latlng, property) {
        var marker = new MarkerWithLabel({
            map: self.map, 
            draggable: false,
            flat: true,
            labelContent: property.bath,
            labelAnchor: new google.maps.Point(22, 0),
            labelClass: "label", // the CSS class for the label
            labelStyle: {opacity: 1},
            icon: 'http://bedstuybid.org/wp-content/uploads/2013/04/blank.png',   
            position: latlng
            });

            self.bounds.extend(latlng);
            self.map.fitBounds(self.bounds);
            self.map.setCenter(convert_offset(self.bounds.getCenter(), x_center_offset, y_center_offset));

            var infoBubble = new InfoBubble({
                maxWidth: 275,
                content: contentString,
                borderRadius: 3,
                disableAutoPan: true
            });

            var residentialString = '';
            if(property['commercial'] != 'commercial') {
                var residentialString='<p class="details">'+property.bed+' br, '+property.bath+' ba';
            }

            var contentString =
            '<div class="info-content">'+
            '<a href="'+property.permalink+'"><img class="left" src="'+property.thumb+'" /></a>'+
            '<div class="listing-details left">'+
            '<h3><a href="'+property.permalink+'">'+property.street+'</a></h3>'+
            '<p class="location">'+property.city+', '+property.state+'&nbsp;'+property.zip+'</p>'+
            // '<p class="price"><strong>'+property.fullPrice+'</strong></p>'+residentialString+', '+property.size+'</p></div>'+
            '</div>';

            var tabContent =
            '<div class="info-content">'+
            '<img class="left" src="'+property.agentThumb+'" />'+
            '<div class="listing-details left">'+
            '<h3>'+property.agentName+'</h3>'+
            '<p class="tagline">'+property.agentTagline+'</p>'+
            '<p class="phone"><strong>Tel:</strong> '+property.agentPhone+'</p>'+
            '<p class="email"><a href="mailto:'+property.agentEmail+'">'+property.agentEmail+'</a></p>'+
            '</div>'+
            '</div>';

            infoBubble.addTab('Details', contentString);
            infoBubble.addTab('Contact', tabContent);

            google.maps.event.addListener(marker, 'click', function() {
                if(open_info_window) open_info_window.close();

                if (!infoBubble.isOpen()) {
                    infoBubble.open(self.map, marker);
                    self.map.panTo(convert_offset(this.position, x_info_offset, y_info_offset));
                    open_info_window = infoBubble;
                }
            });

    function geocode_and_place_marker(property) {
       var geocoder = new google.maps.Geocoder();
       var address = property.street+', '+property.city+' '+property.state+', '+property.zip;

           //If latlong exists build the marker, otherwise geocode then build the marker
           if (property['latlong']) {
               var lat = parseFloat(property['latlong'].split(',')[0]),
                    lng = parseFloat(property['latlong'].split(',')[1]);
                var latlng = new google.maps.LatLng(lat,lng);
                build_marker(latlng, property);

           } else {
               geocoder.geocode({ address : address }, function( results, status ) {
                   if(status == google.maps.GeocoderStatus.OK) {
                        var latlng = results[0].geometry.location;
                        build_marker(latlng, property);
                    }
                });
            }
    }

    function init_canvas_projection() {
        function CanvasProjectionOverlay() {}
        CanvasProjectionOverlay.prototype = new google.maps.OverlayView();
        CanvasProjectionOverlay.prototype.constructor = CanvasProjectionOverlay;
        CanvasProjectionOverlay.prototype.onAdd = function(){};
        CanvasProjectionOverlay.prototype.draw = function(){};
        CanvasProjectionOverlay.prototype.onRemove = function(){};

        self.canvasProjectionOverlay = new CanvasProjectionOverlay();
        self.canvasProjectionOverlay.setMap(self.map);
    }

    function convert_offset(latlng, x_offset, y_offset) {
        var proj = self.canvasProjectionOverlay.getProjection();
        var point = proj.fromLatLngToContainerPixel(latlng);
        point.x = point.x + x_offset;
        point.y = point.y + y_offset;
        return proj.fromContainerPixelToLatLng(point);
    }

    self.init_property_map = function (properties, defaultmapcenter) {
        var options = {
            zoom: 1,
            center: new google.maps.LatLng(defaultmapcenter.mapcenter),
            mapTypeId: google.maps.MapTypeId.TERRAIN, 
            disableDefaultUI: true,
            streetViewControl: false
        };

        self.map = new google.maps.Map( document.getElementById( 'map' ), options );
        self.bounds = new google.maps.LatLngBounds();
        init_canvas_projection();

        //wait for idle to give time to grab the projection (for calculating offset)
        var idle_listener = google.maps.event.addListener(self.map, 'idle', function() {
            for (i=0;i<properties.length;i++) {
                geocode_and_place_marker(properties[i]);
            }
            google.maps.event.removeListener(idle_listener);
        });

    }

    return self;

}());