Revert "validation_pool: pool.changes -> pool.candidates, pool.applied."

This reverts commit ff627b430f16161de5d62b390733984692329fe0.

BUG=chromium:557314
TEST=None

Change-Id: I057df80e2208fbce020e878d677e8b1e5f9656d0
Reviewed-on: https://chromium-review.googlesource.com/312965
Reviewed-by: Aviv Keshet <[email protected]>
Reviewed-by: Don Garrett <[email protected]>
Tested-by: Simran Basi <[email protected]>
7 files changed