Chromium like any browser that respects itself, you can use the System Proxy if we have to use one to navigate.
The problem comes when we use it in desktop environments like LXDE o Xfce, who do not have the option to use a Global Proxy. The use of proxy en Chromium it is as simple as putting in a terminal:
$ chromium-browser --proxy-server="servidor:puerto"
But it would be very tedious to have to do this every time we go sailing. Therefore the immediate solution is to edit the file: /usr/share/applications/chromium.desktop. We look for the line that says:
Exec=/usr/bin/chromium %U
And we replace it with:
Exec=/usr/bin/chromium --proxy-server="servidor:puerto"
That should be enough. We can also use Sock Proxy if we use the line:
chromium-browser --proxy-server="socks5://servidor:1080"
You can have much more information in this website.