Remove methods for deprecated CleanUpStrategy policy.

This will be submitted after the change to remove the use of this policy:
https://chromium-review.googlesource.com/#/c/190984/

BUG=chromium:343781
TEST=unit

Change-Id: I8c42906d6b88fb87bbc300eea5a8e53b79bda785
Reviewed-on: https://chromium-review.googlesource.com/191137
Reviewed-by: Bartosz Fabianowski <bartfab@chromium.org>
Tested-by: David Roche <davidroche@chromium.org>
Commit-Queue: David Roche <davidroche@chromium.org>
5 files changed