GitLab

Make policy-forced migration to ext4 report the new
FIRST_SCREEN_START_AUTOMATICALLY UMA stat value instead of
FIRST_SCREEN_RESUME.

The introduction of EncryptionMigrationMode was required to distinguish
between these cases.

BUG=722371

Change-Id: I112406048e82c31762123a32775be445e6e731ab
Reviewed-on: https://chromium-review.googlesource.com/579382Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Reviewed-by: Naoki Fukino <fukino@chromium.org>
Commit-Queue: Pavol Marko <pmarko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488590}