Track JS allocations as they arrive with no affection on performance when tracking is switched off

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 45 matching lines @@
       const char* name,
       v8::ActivityControl* control,
       v8::HeapProfiler::ObjectNameResolver* resolver);
   HeapSnapshot* TakeSnapshot(
       String* name,
       v8::ActivityControl* control,
       v8::HeapProfiler::ObjectNameResolver* resolver);
 
   void StartHeapObjectsTracking();
   void StopHeapObjectsTracking();
+
+  static void RecordObjectAllocationFromMasm(Isolate* isolate,
+                                             Address obj,
+                                             int size);
+
   SnapshotObjectId PushHeapObjectsStats(OutputStream* stream);
   int GetSnapshotsCount();
   HeapSnapshot* GetSnapshot(int index);
   SnapshotObjectId GetSnapshotObjectId(Handle<Object> obj);
   void DeleteAllSnapshots();
 
-  void ObjectMoveEvent(Address from, Address to);
+  void ObjectMoveEvent(Address from, Address to, int size);
+
+  void NewObjectEvent(Address addr, int size);
 
   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();
   }
 
   void SetRetainedObjectInfo(UniqueId id, RetainedObjectInfo* info);
 
+  bool is_tracking_allocations() {
+    return is_tracking_allocations_;
+  }
+
+  bool* is_tracking_allocations_address();
+
+  void StartHeapAllocationsRecording();
+  void StopHeapAllocationsRecording();
+
+  int FindUntrackedObjects();
+
  private:
   Heap* heap() const { return snapshots_->heap(); }
 
   HeapSnapshotsCollection* snapshots_;
   unsigned next_snapshot_uid_;
   List<v8::HeapProfiler::WrapperInfoCallback> wrapper_callbacks_;
+  bool is_tracking_allocations_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_PROFILER_H_