Make minification Entity-friendly.

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;
 
 import '../closure.dart';
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Selectors;
 import '../constants/values.dart';
 import '../common_elements.dart' show CommonElements;
 import '../diagnostics/invariant.dart' show DEBUG_MODE;
 import '../elements/elements.dart'
     show
         ClassElement,
         Element,
         Elements,
-        FieldElement,
         MemberElement,
         MixinApplicationElement;
 import '../elements/entities.dart';
 import '../elements/entity_utils.dart' as utils;
 import '../elements/jumps.dart';
 import '../elements/names.dart';
 import '../elements/resolution_types.dart';
 import '../elements/types.dart';
 import '../js/js.dart' as jsAst;
+import '../js_model/closure.dart';
 import '../universe/call_structure.dart' show CallStructure;
 import '../universe/selector.dart' show Selector, SelectorKind;
 import '../universe/world_builder.dart' show CodegenWorldBuilder;
 import 'package:front_end/src/fasta/scanner/characters.dart';
 import '../util/util.dart';
 import '../world.dart' show ClosedWorld;
 import 'backend.dart';
 import 'constant_system_javascript.dart';
 import 'native_data.dart';
 import 'runtime_types.dart';
@@ skipping 2195 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);
   }
 }