add yiwzhang and ddoman to depot_tools OWNERS

R=sokcevic

Rationale: both of us are member of source team now and we will
need to review CLs from contributors during our oncall rotation
Change-Id: If7a5f3ece668df0ed799653707f7e8378e753f56
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4766323
Auto-Submit: Yiwei Zhang <yiwzhang@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@chromium.org>

OWNERS

@@ -2,9 +2,11 @@ set noparent
 
 ajp@google.com
 aravindvasudev@google.com
+ddoman@chromium.org
 gavinmak@google.com
 jojwang@google.com
 sokcevic@google.com
+yiwzhang@google.com
 
 per-file autoninja*=brucedawson@chromium.org
 per-file autoninja*=dpranke@google.com