Remove BackendClasses and JavaScriptBackendClasses.

pkg/compiler/lib/src/native/enqueue.dart

Index: pkg/compiler/lib/src/native/enqueue.dart
diff --git a/pkg/compiler/lib/src/native/enqueue.dart b/pkg/compiler/lib/src/native/enqueue.dart
index 959d7dce750b828bba1891584f122ec59c77b561..56af887cac412f311e8610c7f4c49b72c46bb1d0 100644
--- a/pkg/compiler/lib/src/native/enqueue.dart
+++ b/pkg/compiler/lib/src/native/enqueue.dart
@@ -2,7 +2,6 @@
 // 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.
 
-import '../common/backend_api.dart';
 import '../common_elements.dart' show CommonElements, ElementEnvironment;
 import '../elements/elements.dart';
 import '../elements/entities.dart';
@@ -53,11 +52,10 @@ abstract class NativeEnqueuerBase implements NativeEnqueuer {
   final CompilerOptions _options;
   final ElementEnvironment _elementEnvironment;
   final CommonElements _commonElements;
-  final BackendClasses _backendClasses;
 
   /// Subclasses of [NativeEnqueuerBase] are constructed by the backend.
-  NativeEnqueuerBase(this._options, this._elementEnvironment,
-      this._commonElements, this._backendClasses);
+  NativeEnqueuerBase(
+      this._options, this._elementEnvironment, this._commonElements);
 
   bool get enableLiveTypeAnalysis => _options.enableNativeLiveTypeAnalysis;
 
@@ -112,7 +110,7 @@ abstract class NativeEnqueuerBase implements NativeEnqueuer {
             type == _commonElements.nullType ||
             type == _commonElements.boolType ||
             _elementEnvironment.isSubtype(type,
-                _elementEnvironment.getRawType(_backendClasses.listClass))) {
+                _elementEnvironment.getRawType(_commonElements.jsArrayClass))) {
           registerInstantiation(type);
         }
         // TODO(johnniwinther): Improve spec string precision to handle type
@@ -197,10 +195,9 @@ class NativeResolutionEnqueuer extends NativeEnqueuerBase {
       CompilerOptions options,
       ElementEnvironment elementEnvironment,
       CommonElements commonElements,
-      BackendClasses backendClasses,
       this._backendUsageBuilder,
       this._nativeClassResolver)
-      : super(options, elementEnvironment, commonElements, backendClasses);
+      : super(options, elementEnvironment, commonElements);
 
   void _registerBackendUse(FunctionEntity element) {
     _backendUsageBuilder.registerBackendFunctionUse(element);
@@ -237,11 +234,10 @@ class NativeCodegenEnqueuer extends NativeEnqueuerBase {
       CompilerOptions options,
       ElementEnvironment elementEnvironment,
       CommonElements commonElements,
-      BackendClasses backendClasses,
       this._emitter,
       this._resolutionEnqueuer,
       this._nativeData)
-      : super(options, elementEnvironment, commonElements, backendClasses);
+      : super(options, elementEnvironment, commonElements);
 
   WorldImpact processNativeClasses(Iterable<LibraryElement> libraries) {
     WorldImpactBuilderImpl impactBuilder = new WorldImpactBuilderImpl();