Extend ash/shelf/*login* ownership to ash/login/OWNERS

Bug: none
Change-Id: Ie5f17bbbbbfed17fc0dc97d98ee0f4c0d41ccd30
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2343037
Auto-Submit: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795972}

ash/shelf/OWNERS

@@ -4,4 +4,6 @@ skuhne@chromium.org
 tbarzic@chromium.org
 xiyuan@chromium.org
 
+per-file *login*=file://ash/login/OWNERS
+
 # COMPONENT: UI>Shell>Shelf