Add charles as owner of tabranker.

Change-Id: I6fe3dd94a248914cd3f86339f7a152fdda3886d0
Reviewed-on: https://chromium-review.googlesource.com/c/1353033Reviewed-by: Andrew Moylan <amoylan@chromium.org>
Commit-Queue: Charles . <charleszhao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611850}

chrome/browser/resource_coordinator/tab_ranker/OWNERS

 set noparent
 amoylan@chromium.org
+charleszhao@chromium.org
 michaelpg@chromium.org