[heap] Tracer: Handle incremental marking scopes

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 321d443caef7603b1cbad727a2e1ff7a34a457d2..fa19c9fad9372d6cecd907493ae7a539b7e862a0 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -622,6 +622,9 @@ void IncrementalMarking::MarkRoots() {
 
 
 void IncrementalMarking::MarkObjectGroups() {
+  TRACE_GC(heap_->tracer(),
+           GCTracer::Scope::MC_INCREMENTAL_FINALIZE_OBJECT_GROUPING);
+
   DCHECK(!heap_->UsingEmbedderHeapTracer());
   DCHECK(!finalize_marking_completed_);
   DCHECK(IsMarking());