Add arthursonzogni@ to content/OWNERS

Change-Id: Ic9f9e2aee6f6546b410eb654b1b5dfaaab4724e9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2556684Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830560}

content/OWNERS

@@ -13,6 +13,7 @@
 # to content-owners@chromium.org.
 
 alexmos@chromium.org
+arthursonzogni@chromium.org
 avi@chromium.org
 clamy@chromium.org
 creis@chromium.org