Issue 29398. Infer instance members using InheritanceManager of the ClassElement.

pkg/analyzer/lib/src/task/dart.dart

Index: pkg/analyzer/lib/src/task/dart.dart
diff --git a/pkg/analyzer/lib/src/task/dart.dart b/pkg/analyzer/lib/src/task/dart.dart
index e309717e8759e5bb6dfa5f2393c408c052049ed2..a7856f9490311fdd1e8cd44ca8cd74738d1130f0 100644
--- a/pkg/analyzer/lib/src/task/dart.dart
+++ b/pkg/analyzer/lib/src/task/dart.dart
@@ -3490,11 +3490,10 @@ class InferInstanceMembersInUnitTask extends SourceBasedAnalysisTask {
     // Infer instance members.
     //
     if (context.analysisOptions.strongMode) {
+      var inheritanceManager = new InheritanceManager(
+          resolutionMap.elementDeclaredByCompilationUnit(unit).library);
       InstanceMemberInferrer inferrer = new InstanceMemberInferrer(
-          typeProvider,
-          new InheritanceManager(
-              resolutionMap.elementDeclaredByCompilationUnit(unit).library),
-          fieldsWithDisabledInference,
+          typeProvider, (_) => inheritanceManager, fieldsWithDisabledInference,
           typeSystem: context.typeSystem);
       inferrer.inferCompilationUnit(unit.element);
     }