Simplify the write barrier.

src/mark-compact-inl.h

 // Copyright 2011 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 21 matching lines @@
 #include "memory.h"
 #include "mark-compact.h"
 
 
 namespace v8 {
 namespace internal {
 
 
 MarkBit Marking::MarkBitFrom(Address addr) {
   MemoryChunk* p = MemoryChunk::FromAddress(addr);
-  return p->markbits()->MarkBitFromIndex(p->AddressToMarkbitIndex(addr),
-                                         p->ContainsOnlyData());
+  return p->markbits()->MarkBitFromIndex(p->AddressToMarkbitIndex(addr));
 }
 
 
 void MarkCompactCollector::SetFlags(int flags) {
   sweep_precisely_ = ((flags & Heap::kMakeHeapIterableMask) != 0);
 }
 
 
 void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
@@ skipping 32 matching lines @@
                             SlotsBuffer::FAIL_ON_OVERFLOW)) {
       EvictEvacuationCandidate(object_page);
     }
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_INL_H_