[heap] GCTracer: Record details for incremental marking

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 f8f19d49967ef2d32956b88cb69cd7fbe6b15451..b9e7c61ba05942c8f9c2ce81a29569d3e2935527 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -744,6 +744,7 @@ void IncrementalMarking::RetainMaps() {
 
 
 void IncrementalMarking::FinalizeIncrementally() {
+  TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_INCREMENTAL_FINALIZE_BODY);
   DCHECK(!finalize_marking_completed_);
   DCHECK(IsMarking());
 
@@ -777,7 +778,6 @@ void IncrementalMarking::FinalizeIncrementally() {
   double end = heap_->MonotonicallyIncreasingTimeInMs();
   double delta = end - start;
   heap_->tracer()->AddMarkingTime(delta);
-  heap_->tracer()->AddIncrementalMarkingFinalizationStep(delta);
   if (FLAG_trace_incremental_marking) {
     PrintF(
         "[IncrementalMarking] Finalize incrementally round %d, "
@@ -1181,6 +1181,7 @@ intptr_t IncrementalMarking::Step(intptr_t allocated_bytes,
     HistogramTimerScope incremental_marking_scope(
         heap_->isolate()->counters()->gc_incremental_marking());
     TRACE_EVENT0("v8", "V8.GCIncrementalMarking");
+    TRACE_GC(heap_->tracer(), GCTracer::Scope::MC_INCREMENTAL);
     double start = heap_->MonotonicallyIncreasingTimeInMs();
 
     // The marking speed is driven either by the allocation rate or by the rate