[loggers] Guard object/code move events using mutexes.

src/heap-profiler.h

 // Copyright 2009-2010 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_PROFILER_H_
 #define V8_HEAP_PROFILER_H_
 
 #include "src/base/smart-pointers.h"
 #include "src/isolate.h"
 #include "src/list.h"
@@ skipping 58 matching lines @@
  private:
   Heap* heap() const;
 
   // Mapping from HeapObject addresses to objects' uids.
   base::SmartPointer<HeapObjectsMap> ids_;
   List<HeapSnapshot*> snapshots_;
   base::SmartPointer<StringsStorage> names_;
   List<v8::HeapProfiler::WrapperInfoCallback> wrapper_callbacks_;
   base::SmartPointer<AllocationTracker> allocation_tracker_;
   bool is_tracking_object_moves_;
+  base::Mutex profiler_mutex_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_PROFILER_H_