Add harringtond to offline_pages/OWNERS

Change-Id: I58554e64c5792ff0e7a6ce8a1ad0a49f86db4945
Reviewed-on: https://chromium-review.googlesource.com/c/1372237
Reviewed-by: Dmitry Titov <dimich@chromium.org>
Commit-Queue: Dan H <harringtond@google.com>
Cr-Commit-Position: refs/heads/master@{#621703}

components/offline_pages/OWNERS

@@ -3,6 +3,7 @@ chili@chromium.org
 dewittj@chromium.org
 dimich@chromium.org
 fgorski@chromium.org
+harringtond@google.com
 jianli@chromium.org
 petewil@chromium.org