Add owners for badge_view files in reading_list.

Add edchin@ and gchatz@ as owners of the badge view files within the
reading list directory.

Bug: none
Change-Id: I4eace37f01184d72a838c519f06cb848e50391bb
Reviewed-on: https://chromium-review.googlesource.com/567798Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Eric Noyau <noyau@chromium.org>
Commit-Queue: Eric Noyau <noyau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485901}

ios/chrome/browser/ui/reading_list/OWNERS

 gambard@chromium.org
 noyau@chromium.org
 olivierrobin@chromium.org
+
+per-file *badge_view*=edchin@chromium.org
+per-file *badge_view*=gchatz@chromium.org