The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3

commit 5b4891f357c8983e5b0dfc8e83adf4a97f227bd3
Author: Balazs Engedy <engedy@chromium.org>
Date: Wed Aug 29 23:08:00 2018

Fix two bugs affecting starting caBLE discovery.

The first bug is that the WebAuthn dialog is never shown if caBLE is
enabled but the |cable_extension| is not provided in the GetAssertion
request.

It's because GetAssertionRequestHandler's constructor will not actually
create and start a FidoCableDiscovery if the request is missing the
|cable_extension| data, while FidoRequestHandlerBase's barrier closure
will still wait for the discovery to start the transport protocol is
marked available in |available_transports|.

The second bug is that caBLE will not be used for a GetAssertion request
if the same web page already issued a MakeCredential request before.

This is because AuthenticatorImpl::MakeCredential will remove caBLE
from |protocols_|. However, the same AuthenticatorImpl instance will be
used to service the GetAssertionRequest, which will already see a
trimmed list of |protocols_| without caBLE, and pass it to
GetAssertionRequestHandler.

Bug:  878877 
Change-Id: I6b7c915fc0de63e6da29399825071734405e424c
Reviewed-on: https://chromium-review.googlesource.com/1194040
Reviewed-by: Chris Palmer <palmer@chromium.org>
Reviewed-by: Kim Paulhamus <kpaulhamus@chromium.org>
Commit-Queue: Balazs Engedy <engedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587355}
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/content/browser/webauth/authenticator_impl.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/content/browser/webauth/authenticator_impl.h
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/content/browser/webauth/authenticator_impl_unittest.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/content/browser/webauth/authenticator_type_converters.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/content/browser/webauth/authenticator_type_converters.h
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/BUILD.gn
[add] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/cable/cable_discovery_data.h
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/cable/fido_cable_discovery.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/cable/fido_cable_discovery.h
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/cable/fido_cable_discovery_unittest.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/ctap_get_assertion_request.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/ctap_get_assertion_request.h
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/fido_discovery.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/fido_discovery.h
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/get_assertion_handler_unittest.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/get_assertion_request_handler.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/make_credential_handler_unittest.cc
[modify] https://crrev.com/5b4891f357c8983e5b0dfc8e83adf4a97f227bd3/device/fido/make_credential_request_handler.cc

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This made the branch, no merges needed.

[Auto-generated comment by a script] We noticed that this issue is targeted for M-70; it appears the fix may have landed after branch point, meaning a merge might be required. Please confirm if a merge is required here - if so add Merge-Request-70 label, otherwise remove Merge-TBD label. Thanks.

Double checked that no merge is required.