Use the HeapObjectIterator to scan-on-scavenge map pages.

src/store-buffer.h

Index: src/store-buffer.h
diff --git a/src/store-buffer.h b/src/store-buffer.h
index 00eb86a805204ef2a0666eb6a726345367c4c209..9101c0eb892435d2ba07950d6906416d1fc7610b 100644
--- a/src/store-buffer.h
+++ b/src/store-buffer.h
@@ -167,18 +167,6 @@ class StoreBuffer {
       RegionCallback region_callback,
       ObjectSlotCallback slot_callback);
 
-  void FindPointersToNewSpaceInMaps(
-    Address start,
-    Address end,
-    ObjectSlotCallback slot_callback,
-    bool clear_maps);
-
-  void FindPointersToNewSpaceInMapsRegion(
-    Address start,
-    Address end,
-    ObjectSlotCallback slot_callback,
-    bool clear_maps);
-
   void IteratePointersInStoreBuffer(ObjectSlotCallback slot_callback,
                                     bool clear_maps);