Revert "Add/Remove functions for disk manipulation."

This reverts commit e35a7e55874ec42157cc051acd1a3d1540258663.

Change-Id: I6994c006859a1de1623741c1f8f2a0bf5b845421
Reviewed-on: https://chromium-review.googlesource.com/193419
Reviewed-by: Bryan Freed <bfreed@chromium.org>
Tested-by: Bryan Freed <bfreed@chromium.org>
Commit-Queue: Bryan Freed <bfreed@chromium.org>