The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/51fa70dc92e6053c2c9dc16774054ddeed8a876e

commit 51fa70dc92e6053c2c9dc16774054ddeed8a876e
Author: Kim Paulhamus <kpaulhamus@chromium.org>
Date: Thu Mar 29 22:03:31 2018

[Webauthn] Handle duplicate registrations with InvalidStateError

This implements the WebauthN spec change that permits returning an immediate
and specific error if the user consented to use a key but it was already
registered with the relying party. Formerly, we had to wait for a timeout
and return the generic "NotAllowedError". This way, RPs can let the user
know the reason that registration failed.

Bug:  814870 
Change-Id: Ib6f0c9cdd5ca7e3f545c8ce6f3c8e641d672783b
Reviewed-on: https://chromium-review.googlesource.com/984725
Reviewed-by: Balazs Engedy <engedy@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Kim Paulhamus <kpaulhamus@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546976}
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/components/password_manager/content/common/credential_manager_mojom_traits.cc
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/content/browser/webauth/authenticator_impl.cc
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/device/fido/fido_constants.h
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/device/fido/u2f_register.cc
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/device/fido/u2f_register_unittest.cc
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/third_party/WebKit/LayoutTests/http/tests/credentialmanager/credentialscontainer-create-basics.html
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/third_party/WebKit/Source/modules/credentialmanager/CredentialManagerTypeConverters.cpp
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/third_party/WebKit/Source/modules/credentialmanager/CredentialsContainer.cpp
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/third_party/WebKit/public/platform/modules/credentialmanager/credential_manager.mojom
[modify] https://crrev.com/51fa70dc92e6053c2c9dc16774054ddeed8a876e/third_party/WebKit/public/platform/modules/webauth/authenticator.mojom

 Issue 813122  has been merged into this issue.