Custom InfoWindow on Google Map v3 with Shadow

I have to add a custom styles Info Window to a Google Map. The rounded border has to go and I have to change the close button.

I've found InfoBox fro开发者_C百科m Google Maps Utility Library which works fine but it doesn't seem to support shadows. Does anybody know of how to achieve this?

Implement the Maps API v3 OverlayView class and use getPanes().floatShadow to get a container into which you can insert a shadow image, and getPanes().floatPane to get a container into which can insert your main infowindow container and content.