Add flag to trace object groups

src/heap/incremental-marking.cc

Index: src/heap/incremental-marking.cc
diff --git a/src/heap/incremental-marking.cc b/src/heap/incremental-marking.cc
index 924b94e1087686f446d654bd8719541b13f58ec4..fa6f72b6f61e7ccc66f1ab94eb38f92fced6cb1d 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -10,8 +10,9 @@
 #include "src/heap/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/heap/mark-compact-inl.h"
-#include "src/heap/objects-visiting.h"
+#include "src/heap/object-groups-tracer.h"
 #include "src/heap/objects-visiting-inl.h"
+#include "src/heap/objects-visiting.h"
 #include "src/tracing/trace-event.h"
 #include "src/v8.h"
 
@@ -619,6 +620,7 @@ void IncrementalMarking::MarkObjectGroups() {
   heap_->mark_compact_collector()->MarkImplicitRefGroups(&MarkObject);
   heap_->isolate()->global_handles()->IterateObjectGroups(
       &visitor, &MarkCompactCollector::IsUnmarkedHeapObjectWithHeap);
+
   heap_->isolate()->global_handles()->RemoveImplicitRefGroups();
   heap_->isolate()->global_handles()->RemoveObjectGroups();
 }