The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9d1a8229a6744d90469b586304f4795d602f050a

commit 9d1a8229a6744d90469b586304f4795d602f050a
Author: Hiroki Nakagawa <nhiroki@chromium.org>
Date: Fri Jun 01 01:05:00 2018

Worker: Change the default credentials option from 'omit' to 'same-origin'

This is a follow-up for the spec change:
https://github.com/whatwg/html/pull/3656

Note that ES Modules for dedicated workers is still behind the flag and this
change doesn't affect applications in the real world.

Bug:  848247 
Change-Id: I25083f3f11f9d13663e16e2f4c137095e9b12b01
Reviewed-on: https://chromium-review.googlesource.com/1080668
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#563465}
[modify] https://crrev.com/9d1a8229a6744d90469b586304f4795d602f050a/third_party/WebKit/LayoutTests/external/wpt/workers/modules/dedicated-worker-options-credentials.html
[modify] https://crrev.com/9d1a8229a6744d90469b586304f4795d602f050a/third_party/blink/renderer/core/workers/worker_options.idl