Use both object grouping and wrapper tracing.

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 372c7501eff508877b9ff685ec9e4565e6a08e16..4132d0b90ca3c261658b31e1d7073aa59d991832 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -2051,7 +2051,8 @@ void MarkCompactCollector::ProcessEphemeralMarking(
     if (UsingEmbedderHeapTracer()) {
       embedder_heap_tracer()->TraceWrappersFrom(wrappers_to_trace_);
       wrappers_to_trace_.clear();
-    } else if (!only_process_harmony_weak_collections) {
+    }
+    if (!only_process_harmony_weak_collections) {
       isolate()->global_handles()->IterateObjectGroups(
           visitor, &IsUnmarkedHeapObjectWithHeap);
       MarkImplicitRefGroups(&MarkCompactMarkingVisitor::MarkObject);