[heap] Always use getter when accessing MarkingDeque

src/heap/mark-compact-inl.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_INL_H_
 #define V8_HEAP_MARK_COMPACT_INL_H_
 
 #include "src/heap/mark-compact.h"
 #include "src/heap/remembered-set.h"
 #include "src/isolate.h"
 
 namespace v8 {
 namespace internal {
 
 void MarkCompactCollector::PushBlack(HeapObject* obj) {
   DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(obj)));
-  if (marking_deque_.Push(obj)) {
+  if (marking_deque()->Push(obj)) {
     MemoryChunk::IncrementLiveBytesFromGC(obj, obj->Size());
   } else {
     MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
     Marking::BlackToGrey(mark_bit);
   }
 }
 
 
 void MarkCompactCollector::UnshiftBlack(HeapObject* obj) {
   DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(obj)));
-  if (!marking_deque_.Unshift(obj)) {
+  if (!marking_deque()->Unshift(obj)) {
     MemoryChunk::IncrementLiveBytesFromGC(obj, -obj->Size());
     MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
     Marking::BlackToGrey(mark_bit);
   }
 }
 
 
 void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   DCHECK(ObjectMarking::MarkBitFrom(obj) == mark_bit);
   if (Marking::IsWhite(mark_bit)) {
@@ skipping 178 matching lines @@
     }
     if (object != nullptr) return object;
   }
   return nullptr;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_INL_H_