Refactor CompilerOutput

pkg/compiler/lib/src/js_backend/backend.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 js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 2246 matching lines @@
 
   void set _closedWorld(ClosedWorld value) {
     _closedWorldCache = value;
   }
 
   /// Called when the compiler starts running the codegen enqueuer. The
   /// [WorldImpact] of enabled backend features is returned.
   WorldImpact onCodegenStart(ClosedWorld closedWorld) {
     _closedWorld = closedWorld;
     _namer = determineNamer(_closedWorld, compiler.codegenWorldBuilder);
-    tracer = new Tracer(_closedWorld, namer, compiler.outputProvider);
+    tracer = new Tracer(_closedWorld, namer, compiler);
     emitter.createEmitter(_namer, _closedWorld);
     lookupMapAnalysis.onCodegenStart();
     if (hasIsolateSupport) {
       return enableIsolateSupport(forResolution: false);
     }
     return const WorldImpact();
   }
 
   /// Called when code generation has been completed.
   void onCodegenEnd() {
@@ skipping 913 matching lines @@
   }
 
   @override
   FieldEntity get symbolField => helpers.symbolImplementationField;
 
   @override
   InterfaceType get symbolType {
     return _env.getRawType(helpers.symbolImplementationClass);
   }
 }