I agree, but… This was in open source software. Chromium. Not just Google Chrome. https://github.com/chromium/chromium/commit/422c736b82e7ee763c67109cde700db81ca7b443

hangout_services/thunk.js (via) 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.

https://simonwillison.net/2024/Jul/9/hangout_servicesthunkjs/