Create Namer and Emitter on codegen start.

pkg/compiler/lib/src/js_emitter/full_emitter/interceptor_emitter.dart

 // Copyright (c) 2013, 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.full_emitter;
 
 class InterceptorEmitter extends CodeEmitterHelper {
+  final ClosedWorld closedWorld;
   final Set<jsAst.Name> interceptorInvocationNames = new Set<jsAst.Name>();
 
+  InterceptorEmitter(this.closedWorld);
+
   void recordMangledNameOfMemberMethod(
       FunctionElement member, jsAst.Name name) {
     if (backend.isInterceptedMethod(member)) {
       interceptorInvocationNames.add(name);
     }
   }
 
   jsAst.Expression buildGetInterceptorMethod(
       jsAst.Name key, Set<ClassElement> classes) {
     InterceptorStubGenerator stubGenerator =
-        new InterceptorStubGenerator(compiler, namer, backend);
+        new InterceptorStubGenerator(compiler, namer, backend, closedWorld);
     jsAst.Expression function =
         stubGenerator.generateGetInterceptorMethod(classes);
 
     return function;
   }
 
   /**
    * Emit all versions of the [:getInterceptor:] method.
    */
   jsAst.Statement buildGetInterceptorMethods() {
@@ skipping 15 matching lines @@
 
     return new jsAst.Block(parts);
   }
 
   jsAst.Statement buildOneShotInterceptors() {
     List<jsAst.Statement> parts = <jsAst.Statement>[];
     Iterable<jsAst.Name> names = backend.oneShotInterceptors.keys.toList()
       ..sort();
 
     InterceptorStubGenerator stubGenerator =
-        new InterceptorStubGenerator(compiler, namer, backend);
+        new InterceptorStubGenerator(compiler, namer, backend, closedWorld);
     String globalObject =
         namer.globalObjectFor(backend.helpers.interceptorsLibrary);
     for (jsAst.Name name in names) {
       jsAst.Expression function =
           stubGenerator.generateOneShotInterceptor(name);
       parts.add(js.statement('${globalObject}.# = #', [name, function]));
     }
 
     return new jsAst.Block(parts);
   }
@@ skipping 27 matching lines @@
    */
   jsAst.Statement buildTypeToInterceptorMap(Program program) {
     jsAst.Expression array = program.typeToInterceptorMap;
     if (array == null) return js.comment("Empty type-to-interceptor map.");
 
     jsAst.Expression typeToInterceptorMap = emitter
         .generateEmbeddedGlobalAccess(embeddedNames.TYPE_TO_INTERCEPTOR_MAP);
     return js.statement('# = #', [typeToInterceptorMap, array]);
   }
 }