Implement a fake U2F device for testing

Bug: 785955
Change-Id: I9e55da4b8a3f6f1abb1246d14281cc99c7594dc5
Reviewed-on: https://chromium-review.googlesource.com/939737
Reviewed-by: Kim Paulhamus <[email protected]>
Reviewed-by: Balazs Engedy <[email protected]>
Reviewed-by: Jan Wilken Dörrie <[email protected]>
Commit-Queue: Arnar Birgisson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#542675}
7 files changed