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. Luca says this - I'm inclined to agree: ``` This is interesting because it is a clear violation of the idea that browser vendors should not give preference to their websites over anyone elses. ``` <https://simonwillison.net/2024/Jul/9/hangout_servicesthunkjs/> Giacomo