Use Unique<Map> in HTransitionElementsKind.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index 20e64c48f2f7a5e5e6a671ee8d6ba3a96d6d844b..379d64b1153f97bbde7cfe31b2657409ff458926 100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -2355,8 +2355,10 @@ class LTransitionElementsKind V8_FINAL : public LTemplateInstruction<0, 2, 2> {
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
-  Handle<Map> original_map() { return hydrogen()->original_map(); }
-  Handle<Map> transitioned_map() { return hydrogen()->transitioned_map(); }
+  Handle<Map> original_map() { return hydrogen()->original_map().handle(); }
+  Handle<Map> transitioned_map() {
+    return hydrogen()->transitioned_map().handle();
+  }
   ElementsKind from_kind() { return hydrogen()->from_kind(); }
   ElementsKind to_kind() { return hydrogen()->to_kind(); }
 };