In Perforce, which is more or less what Google is using, you can branch any directory within the repo. (You would never branch the whole repo; that makes no se

In Perforce, which is more or less what Google is using, you can branch any directory within the repo. (You would never branch the whole repo; that makes no sense.) So if you wanted to construct a directory with one version of one subdirectory, and a different version of another subdirectory, that's quite straightforward.