dart2js: Track holders better when they are deferred.

pkg/compiler/lib/src/js_emitter/model.dart

 // Copyright (c) 2014, 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.new_js_emitter.model;
 
 import '../js/js.dart' as js show Expression, Statement;
 import '../constants/values.dart' show ConstantValue;
 
 import '../deferred_load.dart' show OutputUnit;
 
 import 'js_emitter.dart' show MetadataCollector;
 
 import '../common.dart';
 
 class Program {
   final List<Fragment> fragments;
+  final List<Holder> holders;
   final bool outputContainsConstantList;
   final bool outputContainsNativeClasses;
   final bool hasIsolateSupport;
   /// A map from load id to the list of fragments that need to be loaded.
   final Map<String, List<Fragment>> loadMap;
 
   // If this field is not `null` then its value must be emitted in the embedded
   // global `TYPE_TO_INTERCEPTOR_MAP`. The map references constants and classes.
   final js.Expression typeToInterceptorMap;
 
   // TODO(floitsch): we should store the metadata directly instead of storing
   // the collector. However, the old emitter still updates the data.
   final MetadataCollector _metadataCollector;
 
   Program(this.fragments,
+          this.holders,
           this.loadMap,
           this.typeToInterceptorMap,
           this._metadataCollector,
           {this.outputContainsNativeClasses,
            this.outputContainsConstantList,
            this.hasIsolateSupport}) {
     assert(outputContainsNativeClasses != null);
     assert(outputContainsConstantList != null);
     assert(hasIsolateSupport != null);
   }
@@ skipping 45 matching lines @@
   /// Output file name without extension.
   final String outputFileName;
 
   Fragment(this.outputUnit,
            this.outputFileName,
            this.libraries,
            this.staticNonFinalFields,
            this.staticLazilyInitializedFields,
            this.constants);
 
-  bool get isMainFragment => mainFragment == this;
-  MainFragment get mainFragment;
+  bool get isMainFragment;
 }
 
 /**
  * The main output file.
  *
  * This code emitted from this [Fragment] must be loaded first. It can then load
  * other [DeferredFragment]s.
  */
 class MainFragment extends Fragment {
   final js.Statement invokeMain;
-  final List<Holder> holders;
 
   MainFragment(OutputUnit outputUnit,
                String outputFileName,
                this.invokeMain,
                List<Library> libraries,
                List<StaticField> staticNonFinalFields,
                List<StaticField> staticLazilyInitializedFields,
-               List<Constant> constants,
-               this.holders)
+               List<Constant> constants)
       : super(outputUnit,
               outputFileName,
               libraries,
               staticNonFinalFields,
               staticLazilyInitializedFields,
               constants);
 
-  MainFragment get mainFragment => this;
+  bool get isMainFragment => true;
 }
 
 /**
  * An output (file) for deferred code.
  */
 class DeferredFragment extends Fragment {
-  final MainFragment mainFragment;
   final String name;
 
-  List<Holder> get holders => mainFragment.holders;
-
   DeferredFragment(OutputUnit outputUnit,
                    String outputFileName,
                    this.name,
-                   this.mainFragment,
                    List<Library> libraries,
                    List<StaticField> staticNonFinalFields,
                    List<StaticField> staticLazilyInitializedFields,
                    List<Constant> constants)
       : super(outputUnit,
               outputFileName,
               libraries,
               staticNonFinalFields,
               staticLazilyInitializedFields,
               constants);
+
+  bool get isMainFragment => false;
 }
 
 class Constant {
   final String name;
   final Holder holder;
   final ConstantValue value;
 
   Constant(this.name, this.holder, this.value);
 }
 
@@ skipping 274 matching lines @@
               tearOffName : tearOffName,
               canBeApplied : canBeApplied,
               canBeReflected : canBeReflected);
 }
 
 class StaticStubMethod extends StubMethod implements StaticMethod {
   Holder holder;
   StaticStubMethod(String name, this.holder, js.Expression code)
       : super(name, code);
 }