Add OWNERS to c/b/resources/chromeos/zip_archiver

BUG=359837
TEST=none

Change-Id: I4fa7e2d67a8140423407a3969fffadda697a71e1
Reviewed-on: https://chromium-review.googlesource.com/566780Reviewed-by: Satoru Takabayashi <satorux@google.com>
Reviewed-by: Satoru Takabayashi <satorux@chromium.org>
Commit-Queue: Satoru Takabayashi <satorux@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485792}

chrome/browser/resources/chromeos/zip_archiver/OWNERS

+yawano@chromium.org
+mtomasz@chromium.org