[heap] Add detailed timers to --trace-gc-nvp MC marking phase.

src/heap/gc-tracer.h

 // Copyright 2014 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.
 
 #ifndef V8_HEAP_GC_TRACER_H_
 #define V8_HEAP_GC_TRACER_H_
 
 #include "src/base/platform/platform.h"
 #include "src/globals.h"
 
@@ skipping 81 matching lines @@
 // GCTracer collects and prints ONE line after each garbage collector
 // invocation IFF --trace_gc is used.
 // TODO(ernstm): Unit tests.
 class GCTracer {
  public:
   class Scope {
    public:
     enum ScopeId {
       EXTERNAL,
       MC_MARK,
+      MC_MARK_FINISH_INCREMENTAL,
+      MC_MARK_PREPARE_CODE_FLUSH,
+      MC_MARK_ROOT,
+      MC_MARK_TOPOPT,
+      MC_MARK_RETAIN_MAPS,
+      MC_MARK_WEAK_CLOSURE,
+      MC_MARK_STRING_TABLE,
+      MC_MARK_WEAK_REFERENCES,
+      MC_MARK_GLOBAL_HANDLES,
+      MC_MARK_CODE_FLUSH,
       MC_SWEEP,
       MC_SWEEP_NEWSPACE,
       MC_SWEEP_OLDSPACE,
       MC_SWEEP_CODE,
       MC_SWEEP_CELL,
       MC_SWEEP_MAP,
       MC_EVACUATE_PAGES,
       MC_UPDATE_NEW_TO_NEW_POINTERS,
       MC_UPDATE_ROOT_TO_NEW_POINTERS,
       MC_UPDATE_OLD_TO_NEW_POINTERS,
@@ skipping 443 matching lines @@
 
   // Counts how many tracers were started without stopping.
   int start_counter_;
 
   DISALLOW_COPY_AND_ASSIGN(GCTracer);
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_GC_TRACER_H_