Make ehmaldonado top level OWNER.

He's been doing great work in depot_tools over last year,
and has sufficient knowledge to know when to review and when to find
better reviewers for this repo.

R=ehmaldonado@chromium.org

Change-Id: Idc8c9103906b9a48b69c4a2743e344d0886a759d
Reviewed-on: https://chromium-review.googlesource.com/1213589Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>

OWNERS

@@ -2,6 +2,7 @@ set noparent
 agable@chromium.org
 bradnelson@chromium.org
 dpranke@chromium.org
+ehmaldonado@chromium.org
 hinoka@chromium.org
 iannucci@chromium.org
 jochen@chromium.org