Key external array map transitions on ElementsKind instead of ExternalArrayType

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index a69b05b38f00fc385b665bba6eea1ea039b3fb24..c748d4604b6107a09f2ddf858ad7d85711f0d5df 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -219,9 +219,9 @@ class Factory {
 
   Handle<Map> GetSlowElementsMap(Handle<Map> map);
 
-  Handle<Map> GetExternalArrayElementsMap(Handle<Map> map,
-                                          ExternalArrayType array_type,
-                                          bool safe_to_add_transition);
+  Handle<Map> GetElementsTransitionMap(Handle<Map> map,
+                                       ElementsKind elements_kind,
+                                       bool safe_to_add_transition);
 
   Handle<FixedArray> CopyFixedArray(Handle<FixedArray> array);