It turns out Google Chrome (via Chromium) includes a default extension which makes extra services available to code running on the *.google.com domains - tweeted about today by Luca Casonato, but the code has been there in the public repo since October 2013 as far as I can tell.
It looks like it’s a way to let Google Hangouts (or presumably its modern predecessors) get additional information from the browser, including the current load on the user’s CPU. Update: On Hacker News a Googler confirms that the Google Meet “troubleshooting” feature uses this to review CPU utilization
The code doesn’t do anything on non-Google domains.
Maybe it’s because you tried it on a non Google site? Idk.