- Remember objects (not addresses) in the old generation containing new pointers.

runtime/vm/scavenger.h

Index: runtime/vm/scavenger.h
===================================================================
--- runtime/vm/scavenger.h	(revision 20732)
+++ runtime/vm/scavenger.h	(working copy)
@@ -105,9 +105,7 @@
     kIterateWeaks = 3,
     // Data
     kStoreBufferEntries = 0,
-    kStoreBufferDuplicates = 1,
-    kStoreBufferBlockEntries = 2,
-    kStoreBufferBlockDuplicates = 3
+    kStoreBufferBlockEntries = 1
   };
 
   uword FirstObjectStart() const { return to_->start() | object_alignment_; }