Use closure conversion in new dart2js backend.

pkg/compiler/lib/src/js_emitter/code_emitter_task.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.
 
 part of dart2js.js_emitter;
 
 const USE_NEW_EMITTER = const bool.fromEnvironment("dart2js.use.new.emitter");
 
 /**
  * Generates the code for all used classes in the program. Static fields (even
@@ skipping 102 matching lines @@
     return emitter.interceptorClassAccess(e);
   }
 
   /// Returns the JS expression representing the type [e].
   ///
   /// The given type [e] might be a Typedef.
   jsAst.Expression typeAccess(Element e) {
     return emitter.typeAccess(e);
   }
 
+  jsAst.Expression closureClassConstructorAccess(ClosureClassElement e) {
+    return emitter.closureClassConstructorAccess(e);
+  }
+
   void registerReadTypeVariable(TypeVariableElement element) {
     readTypeVariables.add(element);
   }
 
   Set<ClassElement> interceptorsReferencedFromConstants() {
     Set<ClassElement> classes = new Set<ClassElement>();
     JavaScriptConstantCompiler handler = backend.constants;
     List<ConstantValue> constants = handler.getConstantsForEmission();
     for (ConstantValue constant in constants) {
       if (constant is InterceptorConstantValue) {
@@ skipping 318 matching lines @@
 
   /// Returns the JS prototype of the given class [e].
   jsAst.Expression prototypeAccess(ClassElement e, bool hasBeenInstantiated);
 
   /// Returns the JS constructor of the given interceptor class [e].
   jsAst.Expression interceptorClassAccess(ClassElement e);
 
   /// Returns the JS expression representing the type [e].
   jsAst.Expression typeAccess(Element e);
 
+  /// Returns the JS constructor for the given closure class [e].
+  jsAst.Expression closureClassConstructorAccess(ClosureClassElement e);
+
   int compareConstants(ConstantValue a, ConstantValue b);
   bool isConstantInlinedOrAlreadyEmitted(ConstantValue constant);
 
   void invalidateCaches();
 }