Adding chrishall to OWNERS for ui/accessibility/ax_language_detection*

R=dmazzoni

Change-Id: I464920afa12ab30208ebf490936ce55d36cf12bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1938868
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719741}

ui/accessibility/OWNERS

@@ -9,5 +9,7 @@ katie@chromium.org
 per-file *.mojom=set noparent
 per-file *.mojom=file://ipc/SECURITY_OWNERS
 
+per-file ax_language_detection*=chrishall@chromium.org
+
 # TEAM: chromium-accessibility@chromium.org
 # COMPONENT: Internals>Accessibility