They can't retract the open source license that already exists for Chromium. Maybe Google could start adding proprietary features to Chrome and close-source those bits, but the code that's out there is already out there.

This is basically what happened to Android as they moved an increasing number of essential features to Play Services.

To be fair, these are mostly integrations with other Google services. I wouldn't expect this to be an OS-level package.

Ironically, this is an example of where it is crucially important Oracle-Google case swings Google's way.

Currently, there are alternative implementations of Play Services that can be installed to replace Google's. However, if it is not fair use to use even the bare bones of an API definition without permission, then we can't even create a compatible implementation of such an API without the copyright holder's permission. In which case, we cannot replace Google Play services with anything else.

Actually, Google already has closed source features in Chrome that are totally not related to Google accounts and/or sync. Take for example Android app support in ChromeOS. It is closed source even though both Chromium and Android are open-source.

I can't picture this happening due to the sheer size of the Electron ecosystem. Do you think there's any precedent for this?

John Deere saying you can’t work on your own tractor? 50 years ago this would have been an insane proposition.

I know it’s not the same but something feels similar to me.

Is there any reason Electron couldn’t switch to, say, Firefox?

Electron is really 100% Chromium. I can't see them switching from it (though it would be nice to have a Firefox-base version).

A Firefox based Electron was tried: Positron. It was scrapped for some reason or other (lack of traction?): https://github.com/mozilla/positron

Why would that matter to anyone but Microsoft?

AFAIK Firefox still exists as does KHTML.

Firefox is down for the count with the recent layoffs. It’s Google’s web to lose in the near future.

Some days it really feels like there is nothing new under the sun.