Chrome user here - I didn't get any notifications or popups like that. Do you have a third-party Chrome extension installed? I know a lot of AV vendors love to auto-install their own cyber-security browser extensions that report stuff like that, so it could be that?
No*, but I visit reactjs.org regularly, so this could also be due to Google tracking me. In full disclosure, I clicked the article thinking it was about ReactJS. I've never used ReactOS, though I've been aware of the project (and visited their webpage) before ReactJS was even a thing.
Edit: This could very easily be from AdBlock Plus as well, but the tooltip was under the address bar (and it doesn't reappear when I visit reactos.org)
Edit2: I got this when navigating to https://goggle.com also (that's goGGle, not google). Turned off Lastpass and Adblock Plus to confirm it wasn't from them.
it's definitely a feature that's been around chrome (I'm remembering from both mobile and desktop) for a while. I think the way they show this message has changed over time and probably don't show it if you think you're an advance enough user, that'd be my guess. or maybe you have an extension that stops u from seeing this
