Merge CommonElements and BackendHelpers!

pkg/compiler/lib/src/js_emitter/native_emitter.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 dart2js.js_emitter.native_emitter;
 
 import '../common.dart';
 import '../compiler.dart' show Compiler;
 import '../elements/types.dart' show DartType, FunctionType;
 import '../elements/entities.dart';
 import '../js/js.dart' as jsAst;
 import '../js/js.dart' show js;
-import '../js_backend/backend_helpers.dart' show BackendHelpers;
 import '../js_backend/js_backend.dart' show JavaScriptBackend, Namer;
 import '../js_backend/interceptor_data.dart';
 import '../js_backend/native_data.dart';
 import '../universe/world_builder.dart' show CodegenWorldBuilder;
 
 import 'code_emitter_task.dart' show CodeEmitterTask;
 import 'model.dart';
 
 class NativeEmitter {
   final CodeEmitterTask emitterTask;
@@ skipping 11 matching lines @@
 
   // Caches the methods that have a native body.
   Set<FunctionEntity> nativeMethods = new Set<FunctionEntity>();
 
   NativeEmitter(CodeEmitterTask emitterTask) : this.emitterTask = emitterTask;
 
   Compiler get compiler => emitterTask.compiler;
 
   JavaScriptBackend get backend => compiler.backend;
 
-  BackendHelpers get helpers => backend.helpers;
-
   CodegenWorldBuilder get worldBuilder => compiler.codegenWorldBuilder;
 
   NativeData get nativeData => backend.nativeData;
 
   InterceptorData get interceptorData => backend.interceptorData;
 
   Namer get namer => backend.namer;
 
   /**
    * Prepares native classes for emission. Returns the unneeded classes.
@@ skipping 40 matching lines @@
     Set<Class> seen = new Set<Class>();
 
     Class objectClass = null;
     Class jsInterceptorClass = null;
 
     void walk(Class cls) {
       if (cls.element == compiler.commonElements.objectClass) {
         objectClass = cls;
         return;
       }
-      if (cls.element == helpers.jsInterceptorClass) {
+      if (cls.element == compiler.commonElements.jsInterceptorClass) {
         jsInterceptorClass = cls;
         return;
       }
       if (seen.contains(cls)) return;
       seen.add(cls);
       walk(cls.superclass);
       preOrder.add(cls);
     }
 
     classes.forEach(walk);
@@ skipping 146 matching lines @@
 
     return cls.methods.isEmpty &&
         cls.isChecks.isEmpty &&
         cls.callStubs.isEmpty &&
         !cls.superclass.isMixinApplication &&
         !cls.fields.any(needsAccessor);
   }
 
   void potentiallyConvertDartClosuresToJs(List<jsAst.Statement> statements,
       FunctionEntity member, List<jsAst.Parameter> stubParameters) {
-    FunctionEntity converter = helpers.closureConverter;
+    FunctionEntity converter = compiler.commonElements.closureConverter;
     jsAst.Expression closureConverter =
         emitterTask.staticFunctionAccess(converter);
     worldBuilder.forEachParameter(member, (DartType type, String name) {
       // If [name] is not in [stubParameters], then the parameter is an optional
       // parameter that was not provided for this stub.
       for (jsAst.Parameter stubParameter in stubParameters) {
         if (stubParameter.name == name) {
           type = type.unaliased;
           if (type.isFunctionType) {
             // The parameter type is a function type either directly or through
@@ skipping 80 matching lines @@
     // satisfy a check against [element], in which case an interceptor must be
     // used.  We should also use an interceptor if the check can't be satisfied
     // by a native class in case we get a native instance that tries to spoof
     // the type info.  i.e the criteria for whether or not to use an interceptor
     // is whether the receiver can be native, not the type of the test.
     ClassEntity cls = element;
     if (nativeData.isNativeOrExtendsNative(cls)) return true;
     return isSupertypeOfNativeClass(element);
   }
 }