Merge CommonElements and BackendHelpers!

tests/compiler/dart2js/kernel/closed_world_test.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.
 
 // Tests that the closed world computed from [WorldImpact]s derived from kernel
 // is equivalent to the original computed from resolution.
 library dart2js.kernel.closed_world_test;
 
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/closure.dart';
 import 'package:compiler/src/commandline_options.dart';
 import 'package:compiler/src/common.dart';
 import 'package:compiler/src/common_elements.dart';
 import 'package:compiler/src/common/backend_api.dart';
 import 'package:compiler/src/common/resolution.dart';
 import 'package:compiler/src/common/work.dart';
 import 'package:compiler/src/compiler.dart';
 import 'package:compiler/src/deferred_load.dart';
 import 'package:compiler/src/elements/resolution_types.dart';
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/elements/entities.dart';
 import 'package:compiler/src/elements/types.dart';
 import 'package:compiler/src/enqueue.dart';
 import 'package:compiler/src/js_backend/backend.dart';
-import 'package:compiler/src/js_backend/backend_helpers.dart';
 import 'package:compiler/src/js_backend/backend_impact.dart';
 import 'package:compiler/src/js_backend/backend_usage.dart';
 import 'package:compiler/src/js_backend/custom_elements_analysis.dart';
 import 'package:compiler/src/js_backend/native_data.dart';
 import 'package:compiler/src/js_backend/impact_transformer.dart';
 import 'package:compiler/src/js_backend/interceptor_data.dart';
 import 'package:compiler/src/js_backend/lookup_map_analysis.dart';
 import 'package:compiler/src/js_backend/mirrors_analysis.dart';
 import 'package:compiler/src/js_backend/mirrors_data.dart';
 import 'package:compiler/src/js_backend/no_such_method_registry.dart';
@@ skipping 108 matching lines @@
         verbose: arguments.verbose);
   });
 }
 
 EnqueuerListener createResolutionEnqueuerListener(Compiler compiler) {
   JavaScriptBackend backend = compiler.backend;
   return new ResolutionEnqueuerListener(
       compiler.options,
       compiler.elementEnvironment,
       compiler.commonElements,
-      backend.helpers,
       backend.impacts,
       backend.backendClasses,
       backend.nativeBasicData,
       backend.interceptorDataBuilder,
       backend.backendUsageBuilder,
       backend.rtiNeedBuilder,
       backend.mirrorsDataBuilder,
       backend.noSuchMethodRegistry,
       backend.customElementsResolutionAnalysis,
       backend.lookupMapResolutionAnalysis,
@@ skipping 33 matching lines @@
   final MemberElement element;
 
   KernelWorkItem(this._compiler, this._impactTransformer, this.element);
 
   @override
   WorldImpact run() {
     ResolutionImpact resolutionImpact = build(_compiler, element.resolvedAst);
     return _impactTransformer.transformResolutionImpact(resolutionImpact);
   }
 }