Use private field chunk_

src/mark-compact.h

 // Copyright 2012 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 940 matching lines @@
   friend class Heap;
 };
 
 
 class MarkBitCellIterator BASE_EMBEDDED {
  public:
   explicit MarkBitCellIterator(MemoryChunk* chunk)
       : chunk_(chunk) {
     last_cell_index_ = Bitmap::IndexToCell(
         Bitmap::CellAlignIndex(
-            chunk->AddressToMarkbitIndex(chunk->area_end())));
-    cell_base_ = chunk->area_start();
+            chunk_->AddressToMarkbitIndex(chunk_->area_end())));
+    cell_base_ = chunk_->area_start();
     cell_index_ = Bitmap::IndexToCell(
         Bitmap::CellAlignIndex(
-            chunk->AddressToMarkbitIndex(cell_base_)));
-    cells_ = chunk->markbits()->cells();
+            chunk_->AddressToMarkbitIndex(cell_base_)));
+    cells_ = chunk_->markbits()->cells();
   }
 
   inline bool Done() { return cell_index_ == last_cell_index_; }
 
   inline bool HasNext() { return cell_index_ < last_cell_index_ - 1; }
 
   inline MarkBit::CellType* CurrentCell() {
     ASSERT(cell_index_ == Bitmap::IndexToCell(Bitmap::CellAlignIndex(
         chunk_->AddressToMarkbitIndex(cell_base_))));
     return &cells_[cell_index_];
@@ skipping 33 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_