[heap] Remove unused IntrusiveMarking class.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 46db46b8a34cf2e65ab81c721f71e9fb69e8338e..c4b588f64b7915ff51628d9330c2bf226df697a6 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1007,13 +1007,6 @@ class Heap {
     roots_[kCodeStubsRootIndex] = value;
   }
 
-  // Support for computing object sizes for old objects during GCs. Returns
-  // a function that is guaranteed to be safe for computing object sizes in
-  // the current GC phase.
-  HeapObjectCallback GcSafeSizeOfOldObjectFunction() {
-    return gc_safe_size_of_old_object_;
-  }
-
   // Sets the non_monomorphic_cache_ (only used when expanding the dictionary).
   void public_set_non_monomorphic_cache(UnseededNumberDictionary* value) {
     roots_[kNonMonomorphicCacheRootIndex] = value;
@@ -1901,16 +1894,6 @@ class Heap {
   };
   List<GCEpilogueCallbackPair> gc_epilogue_callbacks_;
 
-  // Support for computing object sizes during GC.
-  HeapObjectCallback gc_safe_size_of_old_object_;
-  static int GcSafeSizeOfOldObject(HeapObject* object);
-
-  // Update the GC state. Called from the mark-compact collector.
-  void MarkMapPointersAsEncoded(bool encoded) {
-    DCHECK(!encoded);
-    gc_safe_size_of_old_object_ = &GcSafeSizeOfOldObject;
-  }
-
   // Code that should be run before and after each GC.  Includes some
   // reporting/verification activities when compiled with DEBUG set.
   void GarbageCollectionPrologue();
@@ -2749,46 +2732,6 @@ class WeakObjectRetainer {
 };
 
 
-// Intrusive object marking uses least significant bit of
-// heap object's map word to mark objects.
-// Normally all map words have least significant bit set
-// because they contain tagged map pointer.
-// If the bit is not set object is marked.
-// All objects should be unmarked before resuming
-// JavaScript execution.
-class IntrusiveMarking {
- public:
-  static bool IsMarked(HeapObject* object) {
-    return (object->map_word().ToRawValue() & kNotMarkedBit) == 0;
-  }
-
-  static void ClearMark(HeapObject* object) {
-    uintptr_t map_word = object->map_word().ToRawValue();
-    object->set_map_word(MapWord::FromRawValue(map_word | kNotMarkedBit));
-    DCHECK(!IsMarked(object));
-  }
-
-  static void SetMark(HeapObject* object) {
-    uintptr_t map_word = object->map_word().ToRawValue();
-    object->set_map_word(MapWord::FromRawValue(map_word & ~kNotMarkedBit));
-    DCHECK(IsMarked(object));
-  }
-
-  static Map* MapOfMarkedObject(HeapObject* object) {
-    uintptr_t map_word = object->map_word().ToRawValue();
-    return MapWord::FromRawValue(map_word | kNotMarkedBit).ToMap();
-  }
-
-  static int SizeOfMarkedObject(HeapObject* object) {
-    return object->SizeFromMap(MapOfMarkedObject(object));
-  }
-
- private:
-  static const uintptr_t kNotMarkedBit = 0x1;
-  STATIC_ASSERT((kHeapObjectTag & kNotMarkedBit) != 0);  // NOLINT
-};
-
-
 #ifdef DEBUG
 // Helper class for tracing paths to a search target Object from all roots.
 // The TracePathFrom() method can be used to trace paths from a specific