[myelin]

Google has a thing called "IARC" (https://opensource.google/documentation/reference/releasing#...) where you make an application with details about what you're done or have done, and if it's approved, you get to own the copyright.

If you want to release it as open source and don't care about owning the copyright, there's a process you can go through to release a new open source project. If you just want to send patches to an existing project, you can generally just do that, as long as the project has an approved open source license and is not on the (short) list of disallowed projects.