Support mixin application equivalence in impact_test.

tests/compiler/dart2js/serialization/test_helper.dart

 // Copyright (c) 2016, 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_helper;
 
 import 'dart:collection';
 import 'package:compiler/src/common/resolution.dart';
 import 'package:compiler/src/constants/expressions.dart';
 import 'package:compiler/src/constants/values.dart';
@@ skipping 645 matching lines @@
         return false;
       case ElementKind.FACTORY_CONSTRUCTOR:
         if (b is KFactoryConstructor) {
           return strategy.test(a, b, 'name', a.name, b.name) &&
               strategy.testElements(
                   a, b, 'enclosingClass', a.enclosingClass, b.enclosingClass);
         }
         return false;
       case ElementKind.CLASS:
         if (b is KClass) {
+          List<InterfaceType> aMixinTypes = [];
+          List<InterfaceType> bMixinTypes = [];
+          ClassElement aClass = a;
+          while (aClass.isMixinApplication) {
+            MixinApplicationElement aMixinApplication = aClass;
+            aMixinTypes.add(aMixinApplication.mixinType);
+            aClass = aMixinApplication.superclass;
+          }
+          KClass bClass = b;
+          while (bClass != null) {
+            InterfaceType mixinType = testing.getMixinTypeForClass(bClass);
+            if (mixinType == null) break;
+            bMixinTypes.add(mixinType);
+            bClass = testing.getSuperclassForClass(bClass);
+          }
+          if (aMixinTypes.isNotEmpty || aMixinTypes.isNotEmpty) {
+            if (aClass.isNamedMixinApplication &&
+                !strategy.test(a, b, 'name', a.name, b.name)) {
+              return false;
+            }
+            return strategy.testTypeLists(
+                a, b, 'mixinTypes', aMixinTypes, bMixinTypes);
+          }
           return strategy.test(a, b, 'name', a.name, b.name) &&
               strategy.testElements(
                   a, b, 'library', a.library, testing.getLibraryForClass(b));
         }
         return false;
       case ElementKind.LIBRARY:
         if (b is KLibrary) {
           LibraryElement libraryA = a;
           return libraryA.canonicalUri == testing.getLibraryUri(b);
         }
@@ skipping 104 matching lines @@
               strategy.testTypeLists(a, b, 'namedParameterTypes',
                   aType.namedParameterTypes, b.namedParameterTypes);
         }
         return false;
       default:
         throw new UnsupportedError('Unsupported equivalence: '
             '$a (${a.runtimeType}) vs $b (${b.runtimeType})');
     }
   }
 }