GitLab

- Added unittests for DataTransferDlpController.
- Changed some functions in DlpRulesManager &
DataTransferDlpController to be virtual, so it'd
be possible to override them in tests.

Bug: 1140528
Change-Id: I36091bb4bc8d2c55cd0ef8749ce46073e9cac689
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2550544
Commit-Queue: Aya Elsayed <ayaelattar@chromium.org>
Reviewed-by: Nikita Podguzov <nikitapodguzov@chromium.org>
Reviewed-by: Sergey Poromov <poromov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830979}