always emit lazy field if overriding static

lib/src/compiler/js_field_storage.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 import 'dart:collection' show HashSet;
 
 import 'package:analyzer/dart/ast/ast.dart' show Identifier;
 import 'package:analyzer/dart/element/element.dart';
 
-import 'extension_types.dart';
-
 class PropertyOverrideResult {
   final bool foundGetter;
   final bool foundSetter;
 
   PropertyOverrideResult(this.foundGetter, this.foundSetter);
 }
 
-PropertyOverrideResult checkForPropertyOverride(FieldElement field,
-    List<ClassElement> superclasses, ExtensionTypeSet extensionTypes) {
+PropertyOverrideResult checkForPropertyOverride(
+    FieldElement field, List<ClassElement> superclasses) {
   bool foundGetter = false;
   bool foundSetter = false;
 
   for (var superclass in superclasses) {
-    // Stop if we reach a native type.
-    if (extensionTypes.isNativeClass(superclass)) break;
-
     var superprop = getProperty(superclass, field.library, field.name);
     if (superprop == null) continue;
 
-    // Static fields can override superclass static fields. However, we need to
-    // handle the case where they override a getter or setter.
-    if (field.isStatic && !superprop.isSynthetic) continue;
-
     var getter = superprop.getter;
     bool hasGetter = getter != null && !getter.isAbstract;
     if (hasGetter) foundGetter = true;
 
     var setter = superprop.setter;
     bool hasSetter = setter != null && !setter.isAbstract;
     if (hasSetter) foundSetter = true;
 
     // Stop if this is an abstract getter/setter
     // TODO(jmesserly): why were we doing this?
@@ skipping 25 matching lines @@
       if (mixin != null) result.add(mixin);
     }
     var supertype = cls.supertype;
     if (supertype == null) break;
 
     cls = supertype.element;
     result.add(cls);
   }
   return result;
 }