[codetrotter]

Click the buttons and see what happens.

It triggers your browser to ask for various permissions for the site.

Also, notable from the Readme:

> currently maintained by Chromium project members, but note that this is not an official Google product.

So presumably if you want to implement something that uses various browser permissions, this site is a good place to start because people working on the Chromium web browser project are using this site to check interactions of the browser permission system.