Mostly use entities in use.dart

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

 // Copyright (c) 2015, 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_backend.helpers;
 
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Uris;
 import '../common/resolution.dart' show Resolution;
 import '../compiler.dart' show Compiler;
@@ skipping 556 matching lines @@
   }
 
   Element get closureConverter {
     return _findHelper('convertDartClosureToJS');
   }
 
   Element get traceFromException {
     return _findHelper('getTraceFromException');
   }
 
-  Element get setRuntimeTypeInfo {
+  MethodElement get setRuntimeTypeInfo {
     return _findHelper('setRuntimeTypeInfo');
   }
 
   Element get getRuntimeTypeInfo {
     return _findHelper('getRuntimeTypeInfo');
   }
 
   MethodElement get getTypeArgumentByIndex {
     return _findHelper('getTypeArgumentByIndex');
   }
@@ skipping 64 matching lines @@
       _cachedCoreHelper('_unresolvedTopLevelGetterError');
   Element get unresolvedTopLevelSetterError =>
       _cachedCoreHelper('_unresolvedTopLevelSetterError');
   Element get unresolvedTopLevelMethodError =>
       _cachedCoreHelper('_unresolvedTopLevelMethodError');
 
   Map<String, Element> _cachedCoreHelpers = <String, Element>{};
   Element _cachedCoreHelper(String name) =>
       _cachedCoreHelpers[name] ??= findCoreHelper(name);
 
-  Element get createRuntimeType {
+  MethodElement get createRuntimeType {
     return _findHelper('createRuntimeType');
   }
 
   Element get fallThroughError {
     return _findHelper("getFallThroughError");
   }
 
   Element get createInvocationMirror {
     return _findHelper('createInvocationMirror');
   }
 
-  Element get cyclicThrowHelper {
+  MethodElement get cyclicThrowHelper {
     return _findHelper("throwCyclicInit");
   }
 
   Element get asyncHelper {
     return _findAsyncHelper("_asyncHelper");
   }
 
   Element get wrapBody {
     return _findAsyncHelper("_wrapJsFunctionForAsync");
   }
@@ skipping 190 matching lines @@
   }
 
   MethodElement get toStringForNativeObject {
     return _findHelper('toStringForNativeObject');
   }
 
   MethodElement get hashCodeForNativeObject {
     return _findHelper('hashCodeForNativeObject');
   }
 }