Every time I launch Google Chrome, I get this notification on top. I'm not going to turn it off, and I click on the x button to close it but it pops up again when I restart Chrome.
Is there any hidden setting or workaround to disable this notification?
Unfortunately, according to the Google 'Product Expert' here, there doesn't seem to be any way to disable the notification. Considering the amount of complaints about it, however, here's hoping they'll release an update soon that will allow turning it off permanently.
That said, this news might cheer you up a little bit:
"Apparently the Chrome v78 update will snooze the pop-up for 14 days." – Source
But I believe that every 14 days for a year isn't that great either!
Personally, I have turned Flash off, and enable it only when prompted by a trusted website – which, fortunately, happens less and less nowadays.
The only way I know this would work is downloading/installing an older version of Chrome (Pre-76) and disabling updates. For the latest version, the only way to get rid of it is actually disabling flash.
I wouldn't recommend you do this for a browser you use as your main, as it entails security issues not limited to flash. But keeping an old version as a "Flash browser" is probably an option. Another option would be Flash Player Projector, although this does derail from the actual question as it isn't usable inside browsers, only on standalone files, and doesn't affect the nag message displayed in chrome.
You can go to
Settings -> Site settings -> Flash
and remove the check on the CheckBox for "Your Flash settings will be kept until you quit Chrome. Ask first".
