Improve equivalence testing of unnamed mixin applications.

tests/compiler/dart2js/serialization/equivalence_test.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.
 
 library dart2js.serialization_test;
 
 import 'dart:io';
 import '../memory_compiler.dart';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/commandline_options.dart';
@@ skipping 373 matching lines @@
   void visitClassElement(ClassElement element1, ClassElement element2) {
     checkElementIdentities(null, null, null, element1, element2);
     check(element1, element2, 'name',
           element1.name, element2.name);
     if (!element1.isUnnamedMixinApplication) {
       check(element1, element2, 'sourcePosition',
           element1.sourcePosition, element2.sourcePosition);
     } else {
       check(element1, element2, 'sourcePosition.uri',
           element1.sourcePosition.uri, element2.sourcePosition.uri);
+      MixinApplicationElement mixin1 = element1;
+      MixinApplicationElement mixin2 = element2;
+      checkElementIdentities(mixin1, mixin2, 'subclass',
+          mixin1.subclass, mixin2.subclass);
+      checkTypes(mixin1, mixin2, 'mixinType',
+          mixin1.mixinType, mixin2.mixinType);
     }
     checkElementIdentities(
         element1, element2, 'library',
         element1.library, element2.library);
     checkElementIdentities(
         element1, element2, 'compilationUnit',
         element1.compilationUnit, element2.compilationUnit);
     checkTypeLists(
         element1, element2, 'typeVariables',
         element1.typeVariables, element2.typeVariables);
@@ skipping 341 matching lines @@
   void visitPrefixElement(PrefixElement element1, PrefixElement element2) {
     check(
         element1, element2, 'isDeferred',
         element1.isDeferred, element2.isDeferred);
     checkElementIdentities(
         element1, element2, 'importedLibrary',
         element1.deferredImport, element2.deferredImport);
     // TODO(johnniwinther): Check members.
   }
 }