Revert of [heap] Enable black allocation when finalizing incremental marking....

Revert of [heap] Enable black allocation when finalizing incremental marking. (patchset #6 id:100001 of https://codereview.chromium.org/2239733002/ )

Reason for revert:
Suspecting this is a roll blocker: https://codereview.chromium.org/2332343002/

#
# Fatal error in ../../v8/src/heap/spaces.h, line 1618
# Check failed: capacity_ >= bytes (25429824 vs. 18446744073709551168).
#

Original issue's description:
> [heap] Enable black allocation when finalizing incremental marking.
>
> BUG=chromium:630386
>
> Committed: https://crrev.com/1ccc742dc326b063999670421e1da0ea124874c0
> Cr-Commit-Position: refs/heads/master@{#39382}

TBR=mlippautz@chromium.org,hpayer@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/2340463005
Cr-Commit-Position: refs/heads/master@{#39397}

src/flag-definitions.h

@@ -743,7 +743,7 @@ DEFINE_INT(min_progress_during_incremental_marking_finalization, 32,
            "least this many unmarked objects")
 DEFINE_INT(max_incremental_marking_finalization_rounds, 3,
            "at most try this many times to finalize incremental marking")
-DEFINE_BOOL(black_allocation, true, "use black allocation")
+DEFINE_BOOL(black_allocation, false, "use black allocation")
 DEFINE_BOOL(concurrent_sweeping, true, "use concurrent sweeping")
 DEFINE_BOOL(parallel_compaction, true, "use parallel compaction")
 DEFINE_BOOL(parallel_pointer_update, true,