[Tracing] Integrate GC object statistics with tracing.

src/heap/object-stats.h

 // Copyright 2015 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_OBJECT_STATS_H_
 #define V8_HEAP_OBJECT_STATS_H_
 
 #include <set>
 
 #include "src/base/ieee754.h"
@@ skipping 17 matching lines @@
         FIRST_CODE_KIND_SUB_TYPE + Code::NUMBER_OF_KINDS,
     FIRST_CODE_AGE_SUB_TYPE =
         FIRST_FIXED_ARRAY_SUB_TYPE + LAST_FIXED_ARRAY_SUB_TYPE + 1,
     OBJECT_STATS_COUNT = FIRST_CODE_AGE_SUB_TYPE + Code::kCodeAgeCount + 1
   };
 
   void ClearObjectStats(bool clear_last_time_stats = false);
 
   void CheckpointObjectStats();
   void PrintJSON(const char* key);
+  void Dump(std::stringstream& stream);
 
   void RecordObjectStats(InstanceType type, size_t size) {
     DCHECK(type <= LAST_TYPE);
     object_counts_[type]++;
     object_sizes_[type] += size;
     size_histogram_[type][HistogramIndexFromSize(size)]++;
   }
 
   void RecordCodeSubTypeStats(int code_sub_type, int code_age, size_t size) {
     int code_sub_type_index = FIRST_CODE_KIND_SUB_TYPE + code_sub_type;
@@ skipping 102 matching lines @@
   Heap* heap_;
   ObjectStats* stats_;
 
   friend class ObjectStatsCollector::CompilationCacheTableVisitor;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_OBJECT_STATS_H_