Google Meet comes with a few features that no other web apps can use
- The troubleshooting modal shows CPU usage [1]
- When screen sharing you can configure the type of screen share (tab/window/screen) in your code
What is surprising here is that there is no public API for both of these. Instead every Chromium build comes with a special Hangout extension pre-installed. Google Meet then uses `postMessage` to communicate with this extension and call APIs that are available in the Extension context.
Here is the code for the extension inside Chromium source
https://source.chromium.org/chromium/chromium/src/+/main:chrome/browser/resources/hangout_services/thunk.js?q=thunk.js
This extension is only available to *.google.com web apps
https://source.chromium.org/chromium/chromium/src/+/main:chrome/browser/resources/hangout_services/manifest.json;l=12
Even though these features might not seem very important, this is still blatant anti-competitive behaviour from google
[1] https://twitter.com/henrylim96/status/1551906796696133637
- The header X-Rlz-String is added to requests that go to the Google home page. This header seems to contain info about language/region, and from which campaign you installed Chrome. Useful for fingerprinting and only Google domains get to have it.
- Incorrect TLS certificates for Google domains are silently and automatically reported to Google.
- X-Chrome-UMA-Enabled and X-Chrome-Variations headers sent to Google domains. The first header seems to be a single "1" value, while the second one seems more useful for fingerprinting.
- Flash-style embeds for old YouTube videos are automatically converted. Other video websites and embeds that no longer work don't get the same treatment.