GitLab

This CL makes sure the `opened` and `notification_dismissed` fields are
shown in the "Sync Node Browser" tab of chrome://sync-internals by
adding some missing code to proto_visitors.h.

Bug: 1164334
Change-Id: I226b37e07709acd8eb164f67c85a22d72cc70e5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2616201Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Victor Vianna <victorvianna@google.com>
Cr-Commit-Position: refs/heads/master@{#841474}