GitLab

This CL includes:
- Enable feature for deleting corrupted passwords
- Enable feature for preventing overwriting the encryption key
- Disable feature that recovers passwords for Sync users (covered
    with the new feature)
- Update tests

Bug: 791541
Change-Id: I1726515dbd74ad2fa64ef1abf419e88c65d48bf0
Reviewed-on: https://chromium-review.googlesource.com/1240300
Commit-Queue: Tonko Sabolčec <tsabolcec@google.com>
Reviewed-by: Christos Froussios <cfroussios@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595168}