Do not follow accessor map transitions when marking descriptor arrays.

src/mark-compact.h

Index: src/mark-compact.h
diff --git a/src/mark-compact.h b/src/mark-compact.h
index 85a4a3b7060cbf57509a5a14055f2ebe1596a89a..93f3fd254823dcad36fadc0d7eb507c0213bfa8e 100644
--- a/src/mark-compact.h
+++ b/src/mark-compact.h
@@ -628,6 +628,9 @@ class MarkCompactCollector {
   // This is for non-incremental marking.
   INLINE(void MarkObject(HeapObject* obj, MarkBit mark_bit));
 
+  INLINE(bool MarkObjectWithoutPush(HeapObject* object));
+  INLINE(void MarkObjectAndPush(HeapObject* value));
+
   // Marks the object black.  This is for non-incremental marking.
   INLINE(void SetMark(HeapObject* obj, MarkBit mark_bit));
 
@@ -645,6 +648,7 @@ class MarkCompactCollector {
 
   // Mark a Map and its DescriptorArray together, skipping transitions.
   void MarkMapContents(Map* map);
+  void MarkAccessorPairSlot(HeapObject* accessors, int offset);
   void MarkDescriptorArray(DescriptorArray* descriptors);
 
   // Mark the heap roots and all objects reachable from them.