The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3efffa04307d986a65a317170bdae835a49a2efe

commit 3efffa04307d986a65a317170bdae835a49a2efe
Author: Yutaka Hirano <yhirano@chromium.org>
Date: Thu Dec 13 06:42:26 2018

Fix Headers mutation with "request-no-cors" guard

https://github.com/whatwg/fetch/pull/833

Bug:  905677 
Change-Id: Ie4141c2b900931ef88e7734cb152b6d28955999f
Reviewed-on: https://chromium-review.googlesource.com/c/1352075
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616230}
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/services/network/public/cpp/cors/cors.cc
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/services/network/public/cpp/cors/cors.h
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/services/network/public/cpp/cors/cors_unittest.cc
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/third_party/blink/renderer/core/fetch/headers.cc
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/third_party/blink/renderer/platform/loader/cors/cors.cc
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/third_party/blink/renderer/platform/loader/cors/cors.h
[delete] https://crrev.com/c74e0b18adf66521ab5dfa7bd724eaaa02374640/third_party/blink/web_tests/external/wpt/fetch/api/headers/headers-no-cors.window-expected.txt
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/third_party/blink/web_tests/external/wpt/fetch/api/headers/headers-no-cors.window.js
[modify] https://crrev.com/3efffa04307d986a65a317170bdae835a49a2efe/third_party/blink/web_tests/http/tests/fetch/script-tests/headers-guard.js