Remove myself as owner of //ash/frame

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I12d82a0c1e4a8dd28157f928170285aa194ae2c5
Reviewed-on: https://chromium-review.googlesource.com/956246Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Peter Kotwicz <pkotwicz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541997}

ash/frame/OWNERS

-pkotwicz@chromium.org