Test ResolutionImpact equivalence.

tests/compiler/dart2js/mock_compiler.dart

 // Copyright (c) 2012, 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 mock_compiler;
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:compiler/compiler.dart' as api;
 import 'package:compiler/compiler_new.dart' as new_api;
 import 'package:compiler/src/common/names.dart' show
     Uris;
 import 'package:compiler/src/constants/expressions.dart';
 import 'package:compiler/src/diagnostics/diagnostic_listener.dart';
 import 'package:compiler/src/diagnostics/source_span.dart';
 import 'package:compiler/src/diagnostics/spannable.dart';
 import 'package:compiler/src/elements/elements.dart';
+import 'package:compiler/src/elements/visitor.dart';
 import 'package:compiler/src/js_backend/backend_helpers.dart'
     show BackendHelpers;
 import 'package:compiler/src/js_backend/lookup_map_analysis.dart'
     show LookupMapAnalysis;
 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/resolution/members.dart';
 import 'package:compiler/src/resolution/registry.dart';
 import 'package:compiler/src/resolution/scope.dart';
 import 'package:compiler/src/resolution/tree_elements.dart';
 import 'package:compiler/src/script.dart';
@@ skipping 310 matching lines @@
 class MockElement extends FunctionElementX {
   MockElement(Element enclosingElement)
       : super('', ElementKind.FUNCTION, Modifiers.EMPTY,
               enclosingElement);
 
   get node => null;
 
   parseNode(_) => null;
 
   bool get hasNode => false;
+
+  accept(ElementVisitor visitor, arg) {
+    return visitor.visitMethodElement(this, arg);
+  }
 }
 
 // TODO(herhut): Disallow warnings and errors during compilation by default.
 MockCompiler compilerFor(String code, Uri uri,
                          {bool analyzeAll: false,
                           bool analyzeOnly: false,
                           Map<String, String> coreSource,
                           bool disableInlining: true,
                           bool minify: false,
                           bool trustTypeAnnotations: false,
@@ skipping 11 matching lines @@
       trustTypeAnnotations: trustTypeAnnotations,
       enableTypeAssertions: enableTypeAssertions,
       enableUserAssertions: enableUserAssertions,
       expectedErrors: expectedErrors,
       expectedWarnings: expectedWarnings,
       outputProvider: outputProvider);
   compiler.registerSource(uri, code);
   compiler.diagnosticHandler = createHandler(compiler, code);
   return compiler;
 }