GitLab

- RemoveKey was accidentally added in https://crrev.com/c/1944502
- Added test to verify JWT payload and base64 url decode public key

Bug: 1029747, 1029483
Change-Id: I248b80898839846a0b0832cf333e49b2c29a8c84
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1950532Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Alex Chau <alexchau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721482}