Output time spent in code flushing in GC NVP trace.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index dc4102739dd64c13ca1510c8f086f91837d10707..9f27a49039225c76c6fede8e20ad1df3295ac87e 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -638,6 +638,7 @@ void Heap::PerformGarbageCollection(AllocationSpace space,
   if (collector == MARK_COMPACTOR) {
     if (FLAG_flush_code) {
       // Flush all potentially unused code.
+      GCTracer::Scope gc_scope(tracer, GCTracer::Scope::MC_FLUSH_CODE);
       FlushCode();
     }
 
@@ -4841,6 +4842,7 @@ GCTracer::~GCTracer() {
     PrintF("mark=%d ", static_cast<int>(scopes_[Scope::MC_MARK]));
     PrintF("sweep=%d ", static_cast<int>(scopes_[Scope::MC_SWEEP]));
     PrintF("compact=%d ", static_cast<int>(scopes_[Scope::MC_COMPACT]));
+    PrintF("flushcode=%d ", static_cast<int>(scopes_[Scope::MC_FLUSH_CODE]));
 
     PrintF("total_size_before=%d ", start_size_);
     PrintF("total_size_after=%d ", Heap::SizeOfObjects());