The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/49c5cc87fc99ed67cb34d006f116dd8142205be7

commit 49c5cc87fc99ed67cb34d006f116dd8142205be7
Author: Jun Choi <hongjunchoi@chromium.org>
Date: Thu Jan 25 17:55:42 2018

Add CTAPRequest objects with empty parameter

AuthenticatorGetInfo, AuthenticatorGetNextAssertion, AuthenticatorReset,
and AuthenticatorCancel commands in CTAP protocol are requests with empty
parameter and are serialized to a single byte that represents command
type. Add object construct to encapsulate/serialize requests with empty
parameter.

Bug:  799355 
Change-Id: I05a876a17bfb3dc1c1ef21d830f330db503856f6
Reviewed-on: https://chromium-review.googlesource.com/851673
Commit-Queue: Jun Choi <hongjunchoi@chromium.org>
Reviewed-by: Kim Paulhamus <kpaulhamus@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531937}
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/BUILD.gn
[add] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_authenticator_request_param.cc
[add] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_authenticator_request_param.h
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_get_assertion_request_param.cc
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_get_assertion_request_param.h
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_make_credential_request_param.cc
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_make_credential_request_param.h
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_request_param.h
[modify] https://crrev.com/49c5cc87fc99ed67cb34d006f116dd8142205be7/device/ctap/ctap_request_unittest.cc