[heap] Fix a markbit data race in deserializer.

BUG=chromium:694255

Change-Id: Icd949cb6cd3c7405dbdf1933f6239851443f87a8
Reviewed-on: https://chromium-review.googlesource.com/542616Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46094}

src/heap/heap.cc

@@ -4275,8 +4275,10 @@ void Heap::RegisterDeserializedObjectsForBlackAllocation(
         HeapObject* obj = HeapObject::FromAddress(addr);
         // There might be grey objects due to black to grey transitions in
         // incremental marking. E.g. see VisitNativeContextIncremental.
-        DCHECK(ObjectMarking::IsBlackOrGrey(obj, MarkingState::Internal(obj)));
-        if (ObjectMarking::IsBlack(obj, MarkingState::Internal(obj))) {
+        DCHECK(ObjectMarking::IsBlackOrGrey<IncrementalMarking::kAtomicity>(
+            obj, MarkingState::Internal(obj)));
+        if (ObjectMarking::IsBlack<IncrementalMarking::kAtomicity>(
+                obj, MarkingState::Internal(obj))) {
           incremental_marking()->ProcessBlackAllocatedObject(obj);
         }
         addr += obj->Size();