Simplify allocation tracker API

src/heap-snapshot-generator.h

 // Copyright 2013 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 278 matching lines @@
 class HeapSnapshotsCollection {
  public:
   explicit HeapSnapshotsCollection(Heap* heap);
   ~HeapSnapshotsCollection();
 
   Heap* heap() const { return ids_.heap(); }
 
   SnapshotObjectId PushHeapObjectsStats(OutputStream* stream) {
     return ids_.PushHeapObjectsStats(stream);
   }
-  void StartHeapObjectsTracking();
+  void StartHeapObjectsTracking(bool track_allocations);
   void StopHeapObjectsTracking();
 
   HeapSnapshot* NewSnapshot(const char* name, unsigned uid);
   void SnapshotGenerationFinished(HeapSnapshot* snapshot);
   List<HeapSnapshot*>* snapshots() { return &snapshots_; }
   void RemoveSnapshot(HeapSnapshot* snapshot);
 
   StringsStorage* names() { return &names_; }
   AllocationTracker* allocation_tracker() { return allocation_tracker_; }
 
@@ skipping 382 matching lines @@
   friend class HeapSnapshotJSONSerializerEnumerator;
   friend class HeapSnapshotJSONSerializerIterator;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshotJSONSerializer);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_SNAPSHOT_GENERATOR_H_