[heap] Make LiveObjectIterator concurrency safe

src/heap/mark-compact.h

 // Copyright 2012 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_MARK_COMPACT_H_
 #define V8_HEAP_MARK_COMPACT_H_
 
 #include <deque>
 
 #include "src/base/bits.h"
@@ skipping 303 matching lines @@
   explicit LiveObjectIterator(MemoryChunk* chunk)
       : chunk_(chunk),
         it_(chunk_),
         cell_base_(it_.CurrentCellBase()),
         current_cell_(*it_.CurrentCell()) {
   }
 
   HeapObject* Next();
 
  private:
+  inline Heap* heap() { return chunk_->heap(); }
+
   MemoryChunk* chunk_;
   MarkBitCellIterator it_;
   Address cell_base_;
   MarkBit::CellType current_cell_;
 };
 
 // -------------------------------------------------------------------------
 // Mark-Compact collector
 class MarkCompactCollector {
  public:
@@ skipping 435 matching lines @@
 
  private:
   MarkCompactCollector* collector_;
 };
 
 V8_EXPORT_PRIVATE const char* AllocationSpaceName(AllocationSpace space);
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_