Introduce a way to grab heap stats.

include/v8-profiler.h

 // Copyright 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
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   /**
    * Takes a heap snapshot and returns it. Title may be an empty string.
    * See HeapSnapshot::Type for types description.
    */
   static const HeapSnapshot* TakeSnapshot(
       Handle<String> title,
       HeapSnapshot::Type type = HeapSnapshot::kFull,
       ActivityControl* control = NULL);
 
   /**
+   * Starts tracking of heap objects population statistics. After calling
+   * this method, all heap objects relocations done by the garbage collector
+   * are being registered.
+   */
+  static void StartHeapObjectsTracking();
+
+  /**
+   * Adds a new time interval entry to the aggregated statistics array. The
+   * time interval entry contains information on the current heap objects
+   * population size. The method also updates aggregated statistics and
+   * reports updates for all previous time intervals via the OutputStream
+   * object. Updates on each time interval are provided as pairs of time
+   * interval index and updated heap objects count.
+   *
+   * StartHeapObjectsTracking must be called before the first call to this
+   * method.
+   */
+  static void PushHeapObjectsStats(OutputStream* stream);
+
+  /**
+   * Stops tracking of heap objects population statistics, cleans up all
+   * collected data. StartHeapObjectsTracking must be called again prior to
+   * calling PushHeapObjectsStats next time.
+   */
+  static void StopHeapObjectsTracking();
+
+  /**
    * Deletes all snapshots taken. All previously returned pointers to
    * snapshots and their contents become invalid after this call.
    */
   static void DeleteAllSnapshots();
 
   /** Binds a callback to embedder's class ID. */
   static void DefineWrapperClass(
       uint16_t class_id,
       WrapperInfoCallback callback);
 
@@ skipping 83 matching lines @@
 };
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 
 
 #endif  // V8_V8_PROFILER_H_