service worker: Opt in to notifications for WPT failures.

See https://groups.google.com/a/chromium.org/d/msg/blink-dev/B-vHX5Bys24/wpaTXIMIBwAJ

Bug: 678905
Change-Id: I12349cab86ec600e61e3488832ad1899953d6f98
Reviewed-on: https://chromium-review.googlesource.com/856477
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#528214}
2 files changed