MarkBit cleanup: They have to be accessed through Marking accessors.

src/heap/store-buffer.cc

 // Copyright 2011 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.
 
 #include <algorithm>
 
 #include "src/v8.h"
 
 #include "src/counters.h"
 #include "src/heap/store-buffer-inl.h"
@@ skipping 362 matching lines @@
       }
     }
   }
   old_top_ = new_top;
   ClearFilteringHashSets();
 
   // Don't scan on scavenge dead large objects.
   LargeObjectIterator it(heap_->lo_space());
   for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) {
     MemoryChunk* chunk = MemoryChunk::FromAddress(object->address());
-    if (chunk->scan_on_scavenge() && !Marking::MarkBitFrom(object).Get()) {
+    if (chunk->scan_on_scavenge() &&
+        Marking::IsWhite(Marking::MarkBitFrom(object))) {
       chunk->set_scan_on_scavenge(false);
     }
   }
 }
 
 
 void StoreBuffer::VerifyValidStoreBufferEntries() {
   for (Address* current = old_start_; current < old_top_; current++) {
     Object** slot = reinterpret_cast<Object**>(*current);
     Object* object = *slot;
@@ skipping 170 matching lines @@
     }
     old_buffer_is_sorted_ = false;
     old_buffer_is_filtered_ = false;
     *old_top_++ = reinterpret_cast<Address>(int_addr << kPointerSizeLog2);
     DCHECK(old_top_ <= old_limit_);
   }
   heap_->isolate()->counters()->store_buffer_compactions()->Increment();
 }
 }
 }  // namespace v8::internal