Add myself to //chrome/browser/ui/views/frame for ash-specific files

Follow up to sky's comment on
https://chromium-review.googlesource.com/c/chromium/src/+/2521691

Bug: none
Change-Id: I045f4fc2828b76688af5d51b9f8a4e573c1a1390
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2522126
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@{#825355}

chrome/browser/ui/views/frame/OWNERS

@@ -2,9 +2,10 @@ bsep@chromium.org
 pkasting@chromium.org
 sky@chromium.org
 
-per-file immersive_mode_controller*=pkotwicz@chromium.org
+per-file *_ash*=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
 per-file system_web_app_non_client_frame_view_browsertest.cc=file://chrome/browser/web_applications/OWNERS
 per-file top_controls_slide_controller*=afakhry@chromium.org