It's not nearly as bad when you have all the people who work on it with you. You look at who caused conflicts and send out emails. Don't land the merge until a

It's not nearly as bad when you have all the people who work on it with you. You look at who caused conflicts and send out emails. Don't land the merge until all commits are resolved. People who don't resolve their changes get in trouble. Not perfect, but there it is. I worked on a chromium based product as well and had the exact same problem. Eventually we came up with a reasonable system for landing commits and just tried out best to build using chromium, but not having actual patches. Worked okay, not great. Better thant he old system of having people do it manually/just porting our changes to each release.