Introduce a way to grab heap stats.

src/heap-profiler.h

 // Copyright 2009-2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 26 matching lines @@
 class HeapSnapshotsCollection;
 
 #define HEAP_PROFILE(heap, call)                                             \
   do {                                                                       \
     v8::internal::HeapProfiler* profiler = heap->isolate()->heap_profiler(); \
     if (profiler != NULL && profiler->is_profiling()) {                      \
       profiler->call;                                                        \
     }                                                                        \
   } while (false)
 
-// The HeapProfiler writes data to the log files, which can be postprocessed
-// to generate .hp files for use by the GHC/Valgrind tool hp2ps.
 class HeapProfiler {
  public:
   static void SetUp();
   static void TearDown();
 
   static HeapSnapshot* TakeSnapshot(const char* name,
                                     int type,
                                     v8::ActivityControl* control);
   static HeapSnapshot* TakeSnapshot(String* name,
                                     int type,
                                     v8::ActivityControl* control);
+
+  static void StartHeapObjectsTracking();
+  static void StopHeapObjectsTracking();
+  static void PushHeapObjectsStats(OutputStream* stream);
   static int GetSnapshotsCount();
   static HeapSnapshot* GetSnapshot(int index);
   static HeapSnapshot* FindSnapshot(unsigned uid);
   static void DeleteAllSnapshots();
 
   void ObjectMoveEvent(Address from, Address to);
 
   void DefineWrapperClass(
       uint16_t class_id, v8::HeapProfiler::WrapperInfoCallback callback);
 
   v8::RetainedObjectInfo* ExecuteWrapperClassCallback(uint16_t class_id,
                                                       Object** wrapper);
   INLINE(bool is_profiling()) {
     return snapshots_->is_tracking_objects();
   }
 
  private:
   HeapProfiler();
   ~HeapProfiler();
   HeapSnapshot* TakeSnapshotImpl(const char* name,
                                  int type,
                                  v8::ActivityControl* control);
   HeapSnapshot* TakeSnapshotImpl(String* name,
                                  int type,
                                  v8::ActivityControl* control);
   void ResetSnapshots();
 
+  void StartHeapObjectsTrackingImpl();
+  void StopHeapObjectsTrackingImpl();
+  void PushHeapObjectsStatsImpl(OutputStream* stream);
+
   HeapSnapshotsCollection* snapshots_;
   unsigned next_snapshot_uid_;
   List<v8::HeapProfiler::WrapperInfoCallback> wrapper_callbacks_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_PROFILER_H_