GitLab

Spec:
https://wicg.github.io/background-fetch/#background-fetch-update-ui-event-update-ui

Bug: 901909
Change-Id: Ia319cd03e41e65c5a6a1f5e61cde6f4ae7705a32
Reviewed-on: https://chromium-review.googlesource.com/c/1320330
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606118}