List<Location> listLocation = new ArrayList<Location>();

@Override
public void onLocationChanged(Location location) {
LatLng newLocation = new LatLng(location.getLatitude(),
                        location.getLongitude());
gmap.moveCamera(CameraUpdateFactory.newLatLngZoom(newLocation, 16));

Marker myMarker = gmap.addMarker(new MarkerOptions()
                    .position(new LatLng(listLocation.get(
                            listLocation.size() - 1).getLatitude(),
                            listLocation.get(listLocation.size() - 1)
                                    .getLongitude())));
myMarker.remove();

gmap.addMarker(new MarkerOptions()
                .title(getResources().getString(
                        R.string.current_location_found)).snippet(cityName)
                .position(newLocation));

gmap.addPolyline(new PolylineOptions()
                .add(new LatLng(listLocation.get(listLocation.size() - 1)
                        .getLatitude(), listLocation.get(
                        listLocation.size() - 1).getLongitude()),
                        new LatLng(location.getLatitude(), location
                                .getLongitude())).width(3)
                .color(Color.BLUE));