Starting making dart2js strong mode clean.

pkg/compiler/lib/src/js_backend/namer.dart

 // Copyright (c) 2011, 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.namer;
 
 import 'dart:collection' show HashMap;
 
 import 'package:js_runtime/shared/embedded_names.dart' show JsGetName;
 
@@ skipping 1906 matching lines @@
         }
       }
       if (indexField != null) {
         _visit(constant.fields[indexField]);
         return;
       }
     }
 
     // TODO(johnniwinther): This should be accessed from a codegen closed world.
     codegenWorldBuilder.forEachInstanceField(constant.type.element,
-        (_, FieldElement field) {
+        (_, FieldEntity field) {
       if (failed) return;
       _visit(constant.fields[field]);
     });
   }
 
   @override
   void visitType(TypeConstantValue constant, [_]) {
     // Generates something like 'Type_String_k8F', using the simple name of the
     // type and a hash to disambiguate the same name in different libraries.
     addRoot('Type');
@@ skipping 106 matching lines @@
   @override
   int visitMap(MapConstantValue constant, [_]) {
     int hash = _hashList(constant.length, constant.keys);
     return _hashList(hash, constant.values);
   }
 
   @override
   int visitConstructed(ConstructedConstantValue constant, [_]) {
     int hash = _hashString(3, constant.type.element.name);
     codegenWorldBuilder.forEachInstanceField(constant.type.element,
-        (_, FieldElement field) {
+        (_, FieldEntity field) {
       hash = _combine(hash, _visit(constant.fields[field]));
     });
     return hash;
   }
 
   @override
   int visitType(TypeConstantValue constant, [_]) {
     ResolutionDartType type = constant.representedType;
     // This name includes the library name and type parameters.
     String name = rtiEncoder.getTypeRepresentationForTypeConstant(type);
@@ skipping 174 matching lines @@
   void addSuggestion(String original, String suggestion) {
     assert(!_suggestedNames.containsKey(original));
     _suggestedNames[original] = suggestion;
   }
 
   bool hasSuggestion(String original) => _suggestedNames.containsKey(original);
   bool isSuggestion(String candidate) {
     return _suggestedNames.containsValue(candidate);
   }
 }