UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/71.0.3578.80 Chrome/71.0.3578.80 Safari/537.36

Steps to reproduce the problem:
1. Click "Install" when updates are available in Ubuntu Mate 18.04. LONG TERM SUPPORT version, which is supposed to be stable.
2. Start web browser
3. Curse
4. Look up how I fixed it the last time.
5. Enter chrome://flags, search for "UI Layout for the browser's top chrome"
6. See that "Normal" is missing, and that none of the other options do what it did.

What is the expected behavior?
Chromium has a reasonably functional user interfaces, somewhat following good established practices on UI design: such as contrast, affordances, etc.

What went wrong?
It looks like crap after a friggin security update.

Did this work before? Yes Chrome 70

Chrome version: 71.0.3578.80  Channel: stable
OS Version: Ubuntu Mate 18.04 LTS x86-64
Flash Version: 

Now I have to replace it with an older version of chromium.
Thanks very much for making my system insecure!