Add go to center with offset on google maps.
google.maps.Map.prototype.setCenterWithOffset = function(latlng, offsetX, offsetY) {
var map = this;
var ov = new google.maps.OverlayView();
ov.onAdd = function() {
var proj = this.getProjection();
var aPoint = proj.fromLatLngToContainerPixel(latlng);
aPoint.x = aPoint.x+offsetX;
aPoint.y = aPoint.y+offsetY;
map.panTo(proj.fromContainerPixelToLatLng(aPoint));
};
ov.draw = function() {};
ov.setMap(this);
};