GitLab

Add ability for users to switch between cameras when scanning
for QR codes on the Activation Code Page.

Screenshot:
https://screenshot.googleplex.com/jacMJUL3HhZAAr2.png

Bug: 1093185
Change-Id: I32282cd62e0b98c72d4a76c5257b3e6f02f111c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2510740
Commit-Queue: Gordon Seto <gordonseto@google.com>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Azeem Arshad <azeemarshad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825032}