Add dom@ to core/script/OWNERS

Bug: None
Change-Id: I4c9d95eef2f96b03e89d9cac08711b9e47c50784
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2367258Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Dominic Farolino <dom@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800818}

third_party/blink/renderer/core/script/OWNERS

+dom@chromium.org
 hiroshige@chromium.org
 jbroman@chromium.org
 kouhei@chromium.org