Add owner for Linux files in chrome/browser/notifications,

Change-Id: I5a1156b00535832bdbe186be8d8407c4e5c341e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1726714Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682396}

chrome/browser/notifications/OWNERS

@@ -6,6 +6,9 @@ peter@chromium.org
 stevenjb@chromium.org
 yoshiki@chromium.org
 
+# Linux files
+per-file *_linux*=thomasanderson@chromium.org
+
 # Mac files
 per-file *_mac*=rsesek@chromium.org