Stop using repository and patch_repository_url properties.
Use self.m.buildbucket.build.input.gerrit_changes[0].{host, project}
instead.

R=ehmaldonado@chromium.org, tandrii@chromium.org

Recipe-Nontrivial-Roll: build
Bug: 877161, 694348
Change-Id: Ideb069c6c8f8b6e6cfb5217f8a04ea18f16d3056
Reviewed-on: https://chromium-review.googlesource.com/1208368
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>