Reuse RuntimeTypesNeedBuilderImpl and _RuntimeTypesNeed for kernel based elements

pkg/compiler/lib/src/kernel/kernel_strategy.dart

 // Copyright (c) 2017, 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.kernel.frontend_strategy;
 
 import '../closure.dart';
 import '../common.dart';
 import '../common_elements.dart';
 import '../common/backend_api.dart';
@@ skipping 81 matching lines @@
   MirrorsDataBuilder createMirrorsDataBuilder() {
     return new MirrorsDataBuilderImpl();
   }
 
   MirrorsResolutionAnalysis createMirrorsResolutionAnalysis(
       JavaScriptBackend backend) {
     return new MirrorsResolutionAnalysisImpl();
   }
 
   RuntimeTypesNeedBuilder createRuntimeTypesNeedBuilder() {
-    return new RuntimeTypesNeedBuilderImpl();
+    return new RuntimeTypesNeedBuilderImpl(
+        elementEnvironment, elementMap.types);
   }
 
   ResolutionWorldBuilder createResolutionWorldBuilder(
       NativeBasicData nativeBasicData,
       SelectorConstraintsStrategy selectorConstraintsStrategy) {
     return new KernelResolutionWorldBuilder(
         elementMap, nativeBasicData, selectorConstraintsStrategy);
   }
 
   WorkItemBuilder createResolutionWorkItemBuilder(
@@ skipping 21 matching lines @@
 
   KernelWorkItem(this._elementMap, this._impactTransformer, this.element);
 
   @override
   WorldImpact run() {
     ResolutionImpact impact = _elementMap.computeWorldImpact(element);
     return _impactTransformer.transformResolutionImpact(impact);
   }
 }
 
-/// Mock implementation of [RuntimeTypesNeedBuilder].
-class RuntimeTypesNeedBuilderImpl implements RuntimeTypesNeedBuilder {
-  @override
-  void registerClassUsingTypeVariableExpression(ClassEntity cls) {}
-
-  @override
-  RuntimeTypesNeed computeRuntimeTypesNeed(
-      ResolutionWorldBuilder resolutionWorldBuilder,
-      ClosedWorld closedWorld,
-      DartTypes types,
-      CommonElements commonElements,
-      BackendUsage backendUsage,
-      {bool enableTypeAssertions}) {
-    throw new UnimplementedError(
-        'RuntimeTypesNeedBuilderImpl.computeRuntimeTypesNeed');
-  }
-
-  @override
-  void registerRtiDependency(ClassEntity element, ClassEntity dependency) {}
-}
-
 /// Mock implementation of [MirrorsDataImpl].
 class MirrorsDataBuilderImpl extends MirrorsDataImpl {
   MirrorsDataBuilderImpl() : super(null, null, null);
 
   @override
   void registerUsedMember(MemberEntity member) {}
 
   @override
   void computeMembersNeededForReflection(
       ResolutionWorldBuilder worldBuilder, ClosedWorld closedWorld) {}
@@ skipping 42 matching lines @@
   void onQueueEmpty(Enqueuer enqueuer, Iterable<ClassEntity> recentClasses) {}
 
   @override
   MirrorsCodegenAnalysis close() {
     throw new UnimplementedError('MirrorsResolutionAnalysisImpl.close');
   }
 
   @override
   void onResolutionComplete() {}
 }