am 161a8e0f: Fix accidental performance regression.

* commit '161a8e0fcbf26922c97654c00b68082be71eeb50':
  Fix accidental performance regression.
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index ece9920..3cc60d9 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -186,7 +186,7 @@
   card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity));
   CHECK(card_table_.get() != NULL) << "Failed to create card table";
 
-  image_mod_union_table_.reset(new accounting::ModUnionTableCardCache(this));
+  image_mod_union_table_.reset(new accounting::ModUnionTableToZygoteAllocspace(this));
   CHECK(image_mod_union_table_.get() != NULL) << "Failed to create image mod-union table";
 
   zygote_mod_union_table_.reset(new accounting::ModUnionTableCardCache(this));