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

src/heap/incremental-marking.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 123 matching lines @@
   }
 }
 
 
 static inline void MarkBlackOrKeepBlack(HeapObject* heap_object,
                                         MarkBit mark_bit, int size) {
   DCHECK(!Marking::IsImpossible(mark_bit));
   if (Marking::IsBlack(mark_bit)) return;
   Marking::MarkBlack(mark_bit);
   MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(), size);
-  DCHECK(Marking::IsBlack(mark_bit));
 }
 
 
 class IncrementalMarkingMarkingVisitor
     : public StaticMarkingVisitor<IncrementalMarkingMarkingVisitor> {
  public:
   static void Initialize() {
     StaticMarkingVisitor<IncrementalMarkingMarkingVisitor>::Initialize();
     table_.Register(kVisitFixedArray, &VisitFixedArrayIncremental);
     table_.Register(kVisitNativeContext, &VisitNativeContextIncremental);
@@ skipping 89 matching lines @@
   INLINE(static void MarkObject(Heap* heap, Object* obj)) {
     IncrementalMarking::MarkObject(heap, HeapObject::cast(obj));
   }
 
   // Marks the object black without pushing it on the marking stack.
   // Returns true if object needed marking and false otherwise.
   INLINE(static bool MarkObjectWithoutPush(Heap* heap, Object* obj)) {
     HeapObject* heap_object = HeapObject::cast(obj);
     MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
     if (Marking::IsWhite(mark_bit)) {
-      mark_bit.Set();
+      Marking::MarkBlack(mark_bit);
       MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
                                             heap_object->Size());
       return true;
     }
     return false;
   }
 };
 
 
 class IncrementalMarkingRootMarkingVisitor : public ObjectVisitor {
@@ skipping 746 matching lines @@
 void IncrementalMarking::IncrementIdleMarkingDelayCounter() {
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 }
 }  // namespace v8::internal