minimum internet
 

Who knows a program to block all connections and only have cinexion in a chrome window?

Windows Firewall (netsh advfirewall)

Block connection of a specific program in GNU/Linux
 

If you're using GNU/Linux, you can try `unshare` as described here. The downside is that you have to do this for every program that you think is trying to access the net.

Any firewall. Put it on learning mode then block everything and create a custom rule for chrome / or block everything and do a whitelist entry for chrome

NetLimiter also is quite easy to use

Try eset smart security with custom firewall rules.

If it is Linux, also in many of the VPS, another practical way is to use UFW (Uncomplicated Firewall) without hassle.

This can be achieved through the built-in firewall. Networking is all prohibited, but one exception.

I guess you can do that with NetLimiter

You need to use NetLimiter Pro for this purpose as Free version only displays the connections

Some protection systems, such as those used on some CAD packages manage to get through firewalls without problem.