Add kenrb as per-file owner in content/browser/frame_host.

Change-Id: I968c0faf6ff19d6225015967d82440b1f80c4f0c
Reviewed-on: https://chromium-review.googlesource.com/c/1333865Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: Charlie Reis <creis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607733}

content/browser/frame_host/OWNERS

@@ -2,3 +2,8 @@
 
 # For surface ID propagation and synchronization
 per-file render_widget_host_view_guest*=fsamuel@chromium.org
+
+# For compositing and input related changes.
+per-file cross_process_frame_connector*=kenrb@chromium.org
+per-file render_frame_host_impl*=kenrb@chromium.org
+per-file render_widget_host_view_guest*=kenrb@chromium.org