Use entities in runtime_types

pkg/compiler/lib/src/js_emitter/metadata_collector.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.
 
 library dart2js.js_emitter.metadata_collector;
 
 import 'package:js_ast/src/precedence.dart' as js_precedence;
 
 import '../common.dart';
 import '../constants/values.dart';
 import '../elements/resolution_types.dart'
     show ResolutionDartType, ResolutionTypedefType;
 import '../deferred_load.dart' show DeferredLoadTask, OutputUnit;
 import '../elements/elements.dart'
     show
         ClassElement,
         ConstructorElement,
         Element,
         FieldElement,
         FunctionElement,
         FunctionSignature,
         LibraryElement,
         MemberElement,
         MethodElement,
         MetadataAnnotation,
         ParameterElement;
 import '../js/js.dart' as jsAst;
 import '../js/js.dart' show js;
-import '../js_backend/backend.dart' show RuntimeTypesEncoder;
 import '../js_backend/constant_handler_javascript.dart';
 import '../js_backend/mirrors_data.dart';
+import '../js_backend/runtime_types.dart' show RuntimeTypesEncoder;
 import '../js_backend/type_variable_handler.dart'
     show TypeVariableCodegenAnalysis;
 import '../options.dart';
 
 import 'code_emitter_task.dart' show Emitter;
 
 /// Represents an entry's position in one of the global metadata arrays.
 ///
 /// [_rc] is used to count the number of references of the token in the
 /// ast for a program.
@@ skipping 421 matching lines @@
     if (token is _ForwardingMetadataEntry && !token.isBound) {
       _foundUnboundToken = true;
     }
   }
 
   bool findUnboundPlaceholders(jsAst.Node node) {
     node.accept(this);
     return _foundUnboundToken;
   }
 }