tree 77092f17552c02b485f9b773ab1a011d8f7ab943
parent d18cd8d34d8c39ce7463b26b894d3b7469ccbb47
author Mitch Rudominer <rudominer@google.com> 1549673105 -0800
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1550010056 +0000

[Registry] Cleans up ProjectConfigs and adds some functionality.

CB-220

This is a follow-on to
https://fuchsia-review.googlesource.com/c/cobalt/+/251890

We clean up ProjectConfigs in a way that is similar to what we did
for ClientConfig. But what we needed to do here was simpler.

- Add comments
- Change terminology from "config" to "registry"
- Add the methods is_empty() and is_single_project().

Change-Id: I1f422ca930b3b78750ebcac7a119618a75fe61ef