var service = ChromeDriverService.CreateDefaultService();
var driver = new ChromeDriver(service);
var form = new Form();
var host = new SeleniumHost();

form.Children.Add(host);
host.DriverService = service;

<Window x:Class="..."
    ...
    xmlns:sh="https://github.com/earloc/AppHost.Selenium">
    <sh:SeleniumHost x:Name="_SeleniumHost" />
</Window>

var service = ChromeDriverService.CreateDefaultService();
var driver = new ChromeDriver(service);
_SeleniumHost.DriverService = service;