Revert of [heap] Enable black allocation when finalizing incremental marking. (patchset #1 id:1 of https://codereview.chromium.org/2224153003/ )

Reason for revert:
crashing on ToT

Original issue's description:
> [heap] Enable black allocation when finalizing incremental marking.
>
> BUG=chromium:630386
>
> Committed: https://crrev.com/bb4e028648a27a6958afc9b5040366b899cda50d
> Cr-Commit-Position: refs/heads/master@{#38487}

TBR=mlippautz@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:630386

Review-Url: https://codereview.chromium.org/2223423003
Cr-Commit-Position: refs/heads/master@{#38490}