[heap] Tracer: Handle incremental marking scopes

src/heap/incremental-marking.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/conversions.h"
 #include "src/heap/gc-idle-time-handler.h"
@@ skipping 604 matching lines @@
 void IncrementalMarking::MarkRoots() {
   DCHECK(!finalize_marking_completed_);
   DCHECK(IsMarking());
 
   IncrementalMarkingRootMarkingVisitor visitor(this);
   heap_->IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
 }
 
 
 void IncrementalMarking::MarkObjectGroups() {
+  TRACE_GC(heap_->tracer(),
+           GCTracer::Scope::MC_INCREMENTAL_FINALIZE_OBJECT_GROUPING);
+
   DCHECK(!heap_->UsingEmbedderHeapTracer());
   DCHECK(!finalize_marking_completed_);
   DCHECK(IsMarking());
 
   IncrementalMarkingRootMarkingVisitor visitor(this);
   heap_->mark_compact_collector()->MarkImplicitRefGroups(&MarkGrey);
   heap_->isolate()->global_handles()->IterateObjectGroups(
       &visitor, &MarkCompactCollector::IsUnmarkedHeapObjectWithHeap);
   heap_->isolate()->global_handles()->RemoveImplicitRefGroups();
   heap_->isolate()->global_handles()->RemoveObjectGroups();
@@ skipping 636 matching lines @@
 void IncrementalMarking::IncrementIdleMarkingDelayCounter() {
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 }  // namespace internal
 }  // namespace v8