Merge CommonElements and BackendHelpers!

tests/compiler/dart2js/kernel/closed_world_test.dart

Index: tests/compiler/dart2js/kernel/closed_world_test.dart
diff --git a/tests/compiler/dart2js/kernel/closed_world_test.dart b/tests/compiler/dart2js/kernel/closed_world_test.dart
index 1f3ae60a8fe0ed3731f61689f8a06c332a90eb55..2f0a9e4f2879b0e7f40bdb20a6e7552e00913f7d 100644
--- a/tests/compiler/dart2js/kernel/closed_world_test.dart
+++ b/tests/compiler/dart2js/kernel/closed_world_test.dart
@@ -18,7 +18,6 @@ import 'package:compiler/src/elements/resolution_types.dart';
 import 'package:compiler/src/elements/elements.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';
@@ -144,7 +143,6 @@ EnqueuerListener createResolutionEnqueuerListener(Compiler compiler) {
       compiler.options,
       compiler.elementEnvironment,
       compiler.commonElements,
-      backend.helpers,
       backend.impacts,
       backend.backendClasses,
       backend.nativeBasicData,
@@ -167,9 +165,7 @@ EnqueuerListener createKernelResolutionEnqueuerListener(CompilerOptions options,
     DeferredLoadTask deferredLoadTask, KernelWorldBuilder worldBuilder) {
   ElementEnvironment elementEnvironment = worldBuilder.elementEnvironment;
   CommonElements commonElements = worldBuilder.commonElements;
-  BackendHelpers helpers =
-      new BackendHelpers(elementEnvironment, commonElements);
-  BackendImpacts impacts = new BackendImpacts(options, commonElements, helpers);
+  BackendImpacts impacts = new BackendImpacts(options, commonElements);
 
   // TODO(johnniwinther): Create Kernel based implementations for these:
   NativeBasicData nativeBasicData;
@@ -180,20 +176,19 @@ EnqueuerListener createKernelResolutionEnqueuerListener(CompilerOptions options,
   MirrorsResolutionAnalysis mirrorsResolutionAnalysis;
 
   BackendClasses backendClasses = new JavaScriptBackendClasses(
-      elementEnvironment, helpers, nativeBasicData);
+      elementEnvironment, commonElements, nativeBasicData);
   InterceptorDataBuilder interceptorDataBuilder =
       new InterceptorDataBuilderImpl(
-          nativeBasicData, helpers, elementEnvironment, commonElements);
+          nativeBasicData, elementEnvironment, commonElements);
   BackendUsageBuilder backendUsageBuilder =
-      new BackendUsageBuilderImpl(commonElements, helpers);
+      new BackendUsageBuilderImpl(commonElements);
   NoSuchMethodRegistry noSuchMethodRegistry = new NoSuchMethodRegistry(
-      helpers, new KernelNoSuchMethodResolver(worldBuilder));
+      commonElements, new KernelNoSuchMethodResolver(worldBuilder));
   NativeResolutionEnqueuer nativeResolutionEnqueuer =
       new NativeResolutionEnqueuer(
           options,
           elementEnvironment,
           commonElements,
-          helpers,
           backendClasses,
           backendUsageBuilder,
           new KernelNativeClassResolver(worldBuilder));
@@ -202,7 +197,6 @@ EnqueuerListener createKernelResolutionEnqueuerListener(CompilerOptions options,
       options,
       elementEnvironment,
       commonElements,
-      helpers,
       impacts,
       backendClasses,
       nativeBasicData,