GitLab

Add sheet view to show when prompting users to use their phone as a
security key to authenticate via the WebAuthN API.

Bug: 847985
Change-Id: I0bb605bf470456f5f29111834f69a71abfbe0430
Reviewed-on: https://chromium-review.googlesource.com/1177445
Commit-Queue: Jun Choi <hongjunchoi@chromium.org>
Reviewed-by: Balazs Engedy <engedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583892}