GitLab

Implement function to extract U2F check only sign command from
CtapMakeCredentialRequest. This is used to iterate through key handles
in the exclude list to prevent duplicate registration.

Bug: 798573
Change-Id: I51ab3dc21c6a7229e99dd513dae4ec9322014a75
Reviewed-on: https://chromium-review.googlesource.com/1032257Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Jun Choi <hongjunchoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555863}