[heap] Refactor marking deque.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index bc501b066e949b933644083f10dc6d49f6a7df85..868aec371e2623ed034c1dfaf1116893e0ea43aa 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1456,11 +1456,7 @@ void Heap::MarkCompactEpilogue() {
   PreprocessStackTraces();
   DCHECK(incremental_marking()->IsStopped());
 
-  // We finished a marking cycle. We can uncommit the marking deque until
-  // we start marking again.
-  mark_compact_collector()->marking_deque()->Uninitialize();
-  mark_compact_collector()->EnsureMarkingDequeIsCommitted(
-      MarkCompactCollector::kMinMarkingDequeSize);
+  mark_compact_collector()->marking_deque()->StopUsing();
 }