tracing: Add skyostil@ + eseckler@ to owners.

Change-Id: If0008c4455008050764efa1935af2473d438c063
Reviewed-on: https://chromium-review.googlesource.com/c/1451857
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Reviewed-by: oysteine <oysteine@chromium.org>
Reviewed-by: Primiano Tucci <primiano@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#629084}

base/trace_event/OWNERS

 chiniforooshan@chromium.org
+eseckler@chromium.org
 oysteine@chromium.org
 primiano@chromium.org
+skyostil@chromium.org
 per-file trace_event_android.cc=wangxianzhu@chromium.org
 
 # For memory-infra related changes