[heap] Prepare IncrementalMarking::VisitObject for concurrent marking.

src/heap/incremental-marking.h

Index: src/heap/incremental-marking.h
diff --git a/src/heap/incremental-marking.h b/src/heap/incremental-marking.h
index 7945e60b3ce40d8c87b055a6c3d9eeeb24c5663f..9f8137641b43caa5ecd296dae810ec340b168585 100644
--- a/src/heap/incremental-marking.h
+++ b/src/heap/incremental-marking.h
@@ -314,6 +314,7 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
       intptr_t bytes_to_process,
       ForceCompletionAction completion = DO_NOT_FORCE_COMPLETION));
 
+  INLINE(bool IsFixedArrayWithProgressBar(HeapObject* object));
   INLINE(void VisitObject(Map* map, HeapObject* obj, int size));
 
   void IncrementIdleMarkingDelayCounter();