GitLab

- Decouple the EmptyViewCoordinator from the underlying model.
- Add back the concept of loading to the View.

Change-Id: I568fcdc32af7aaf42908c56981538c02cc4f61ed
Reviewed-on: https://chromium-review.googlesource.com/1150840
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579522}