[Tracing] Fix runtime call stats tracing for GC.

src/heap/gc-tracer.cc

Index: src/heap/gc-tracer.cc
diff --git a/src/heap/gc-tracer.cc b/src/heap/gc-tracer.cc
index 98be41d3693be9e79c2faf20e077f7d13093668f..c58aa9b5ea9738a69f1e57a73aad065c06503235 100644
--- a/src/heap/gc-tracer.cc
+++ b/src/heap/gc-tracer.cc
@@ -24,24 +24,30 @@ static intptr_t CountTotalHolesSize(Heap* heap) {
 GCTracer::Scope::Scope(GCTracer* tracer, ScopeId scope)
     : tracer_(tracer), scope_(scope) {
   start_time_ = tracer_->heap_->MonotonicallyIncreasingTimeInMs();
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Enter(
+        tracer_->heap_->isolate()->counters()->tracing_runtime_call_stats(),
+        &timer_, &RuntimeCallStats::GC);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Enter(
         tracer_->heap_->isolate()->counters()->runtime_call_stats(), &timer_,
         &RuntimeCallStats::GC);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }
 
 GCTracer::Scope::~Scope() {
   tracer_->AddScopeSample(
       scope_, tracer_->heap_->MonotonicallyIncreasingTimeInMs() - start_time_);
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Leave(
+        tracer_->heap_->isolate()->counters()->tracing_runtime_call_stats(),
+        &timer_);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Leave(
         tracer_->heap_->isolate()->counters()->runtime_call_stats(), &timer_);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }
 
 const char* GCTracer::Scope::Name(ScopeId id) {
@@ -208,12 +214,15 @@ void GCTracer::Start(GarbageCollector collector, const char* gc_reason,
       start_time, committed_memory);
   heap_->isolate()->counters()->aggregated_memory_heap_used()->AddSample(
       start_time, used_memory);
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Enter(
+        heap_->isolate()->counters()->tracing_runtime_call_stats(), &timer_,
+        &RuntimeCallStats::GC);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Enter(heap_->isolate()->counters()->runtime_call_stats(),
                             &timer_, &RuntimeCallStats::GC);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }
 
 void GCTracer::MergeBaseline(const Event& baseline) {
@@ -314,12 +323,14 @@ void GCTracer::Stop(GarbageCollector collector) {
     heap_->PrintShortHeapStatistics();
   }
 
-  // TODO(cbruni): remove once we fully moved to a trace-based system.
-  if (FLAG_runtime_call_stats) {
+  if (TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED()) {
+    RuntimeCallStats::Leave(
+        heap_->isolate()->counters()->tracing_runtime_call_stats(), &timer_);
+  } else if (FLAG_runtime_call_stats) {
+    // TODO(cbruni): remove once we fully moved to a trace-based system.
     RuntimeCallStats::Leave(heap_->isolate()->counters()->runtime_call_stats(),
                             &timer_);
   }
-  // TODO(lpy): Add a tracing equivalent for the runtime call stats.
 }