Add myself as an owner of *_chromeos* in //c/b/ui/views/frame

For lacros, some files there are being renamed from _ash to _chromeos.
I'm an owner of _ash, so make myself an owner of _chromeos also.

Bug: 1113900
Change-Id: I9d96bfa14fa7d52a2ce32b1bdc156b6be0f33930
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533279
Auto-Submit: James Cook <jamescook@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826469}

chrome/browser/ui/views/frame/OWNERS

@@ -3,6 +3,7 @@ pkasting@chromium.org
 sky@chromium.org
 
 per-file *_ash*=jamescook@chromium.org
+per-file *_chromeos*=jamescook@chromium.org
 per-file *x11*=thomasanderson@chromium.org
 per-file desktop_linux_browser_frame_view*=thomasanderson@chromium.org
 per-file immersive_mode_controller*=pkotwicz@chromium.org