GitLab

This updates the consent flow to
1) Enable revocation via the consent activity
2) Only present the privacy preference when the user has consented
3) Have the privacy preference launch the consent activity for revocation
instead of being a checkbox

Bug:902490

Change-Id: I34fdc210ee03db100ab9c310ab5fe3d9cda15d76
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1481739
Commit-Queue: Patrick Noland <pnoland@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638261}