- Remove GetChangeApprovalStatus and GetFilesApprovalStatus.
- Make host, project and branch part of GerritClient.
- Rename ListOwnersForFile to ListOwners.

Change-Id: I1f610a64f0217ce54e5ce4a210026535adc1c2e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2587268
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Gavin Mak <gavinmak@google.com>