Merge CommonElements and BackendHelpers!

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

Index: pkg/compiler/lib/src/native/resolver.dart
diff --git a/pkg/compiler/lib/src/native/resolver.dart b/pkg/compiler/lib/src/native/resolver.dart
index 5d055ccd356883267dd2f0a6a60d668862a1cda7..b7163e9a559a7c88cc5b0816bc9d2ef3b9ba2a82 100644
--- a/pkg/compiler/lib/src/native/resolver.dart
+++ b/pkg/compiler/lib/src/native/resolver.dart
@@ -7,6 +7,7 @@ import 'package:front_end/src/fasta/scanner.dart'
 import 'package:front_end/src/fasta/scanner.dart' as Tokens show EOF_TOKEN;
 
 import '../common.dart';
+import '../common_elements.dart' show CommonElements;
 import '../common/backend_api.dart';
 import '../common/resolution.dart';
 import '../compiler.dart' show Compiler;
@@ -23,7 +24,6 @@ import '../elements/elements.dart'
 import '../elements/entities.dart';
 import '../elements/modelx.dart' show FunctionElementX, MetadataAnnotationX;
 import '../elements/resolution_types.dart' show ResolutionDartType;
-import '../js_backend/backend_helpers.dart';
 import '../js_backend/js_backend.dart';
 import '../js_backend/native_data.dart';
 import '../patch_parser.dart';
@@ -227,7 +227,8 @@ class NativeDataResolverImpl implements NativeDataResolver {
   /// present.
   String _findJsNameFromAnnotation(Element element) {
     String name = null;
-    ClassElement annotationClass = _backend.helpers.annotationJSNameClass;
+    ClassElement annotationClass =
+        _compiler.commonElements.annotationJSNameClass;
     for (MetadataAnnotation annotation in element.implementation.metadata) {
       annotation.ensureResolved(_compiler.resolution);
       ConstantValue value =
@@ -319,7 +320,7 @@ class NativeAnnotationHandler extends EagerAnnotationHandler<String> {
     ResolutionDartType annotationType =
         constant.getType(compiler.commonElements);
     if (annotationType.element !=
-        compiler.backend.helpers.nativeAnnotationClass) {
+        compiler.commonElements.nativeAnnotationClass) {
       DiagnosticReporter reporter = compiler.reporter;
       reporter.internalError(annotation, 'Invalid @Native(...) annotation.');
     }
@@ -373,9 +374,8 @@ class JsInteropAnnotationHandler implements EagerAnnotationHandler<bool> {
   @override
   void validate(Compiler compiler, Element element,
       MetadataAnnotation annotation, ConstantValue constant) {
-    JavaScriptBackend backend = compiler.backend;
     ResolutionDartType type = constant.getType(compiler.commonElements);
-    if (type.element != backend.helpers.jsAnnotationClass) {
+    if (type.element != compiler.commonElements.jsAnnotationClass) {
       compiler.reporter
           .internalError(annotation, 'Invalid @JS(...) annotation.');
     }
@@ -392,21 +392,21 @@ abstract class NativeClassResolver {
 class NativeClassResolverImpl implements NativeClassResolver {
   final DiagnosticReporter _reporter;
   final Resolution _resolution;
-  final BackendHelpers _helpers;
+  final CommonElements _commonElements;
   final NativeBasicData _nativeBasicData;
 
   Map<String, ClassElement> _tagOwner = new Map<String, ClassElement>();
 
-  NativeClassResolverImpl(
-      this._resolution, this._reporter, this._helpers, this._nativeBasicData);
+  NativeClassResolverImpl(this._resolution, this._reporter,
+      this._commonElements, this._nativeBasicData);
 
   Iterable<ClassElement> computeNativeClasses(
       Iterable<LibraryElement> libraries) {
     Set<ClassElement> nativeClasses = new Set<ClassElement>();
     libraries.forEach((l) => _processNativeClassesInLibrary(l, nativeClasses));
-    if (_helpers.isolateHelperLibrary != null) {
+    if (_commonElements.isolateHelperLibrary != null) {
       _processNativeClassesInLibrary(
-          _helpers.isolateHelperLibrary, nativeClasses);
+          _commonElements.isolateHelperLibrary, nativeClasses);
     }
     _processSubclassesOfNativeClasses(libraries, nativeClasses);
     return nativeClasses;