If you build a WebBrowser control based application you will notice that Geolocation does not work properly. You do not get the prompt to accept the website “wants to track your physical location”. Because you do not get that prompt, you cannot accept this security prompt and you will not be able to use Geolocation.
The only current workaround is to add the site to visit the site with the full browser, then when prompted with the security challenge, go to ‘Options for this site’ and select ‘Allways allow’. That way you will no longer get that security challenge and you control will work for that site.