Adjust native field wrapper field count.

lib/dom/src/native_DOMWrapperBase.dart

Index: lib/dom/src/native_DOMWrapperBase.dart
diff --git a/lib/dom/src/native_DOMWrapperBase.dart b/lib/dom/src/native_DOMWrapperBase.dart
index db1f3e7e6e8d0788290e594bb7128ff5a22cc595..cd9ae886710ae7c3f37d8ce479f830c1e0dc4a60 100644
--- a/lib/dom/src/native_DOMWrapperBase.dart
+++ b/lib/dom/src/native_DOMWrapperBase.dart
@@ -2,6 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-class DOMWrapperBase extends NativeFieldWrapperClass2 implements DOMType {
+class DOMWrapperBase extends NativeFieldWrapperClass1 implements DOMType {
   var dartObjectLocalStorage;
 }