[heap] Remove ObjectMarking::ClearMarkBit.

BUG=chromium:694255

Review-Url: https://codereview.chromium.org/2735713002
Cr-Commit-Position: refs/heads/master@{#43610}

src/heap/mark-compact.h

@@ -72,11 +72,6 @@ class ObjectMarking : public AllStatic {
     return Marking::IsBlackOrGrey(MarkBitFrom<mode>(obj));
   }
 
-  template <MarkingMode mode = MarkingMode::FULL>
-  V8_INLINE static void ClearMarkBit(HeapObject* obj) {
-    Marking::MarkWhite(MarkBitFrom<mode>(obj));
-  }
-
   template <MarkingMode mode = MarkingMode::FULL>
   V8_INLINE static void BlackToGrey(HeapObject* obj) {
     DCHECK(IsBlack<mode>(obj));

src/heap/spaces.cc

@@ -3080,7 +3080,7 @@ void LargeObjectSpace::ClearMarkingStateOfLiveObjects() {
   LargeObjectIterator it(this);
   for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
     if (ObjectMarking::IsBlackOrGrey(obj)) {
-      ObjectMarking::ClearMarkBit(obj);
+      Marking::MarkWhite(ObjectMarking::MarkBitFrom(obj));
       MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
       chunk->ResetProgressBar();
       chunk->ResetLiveBytes();