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

pkg/analyzer/test/src/summary/top_level_inference_test.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.
 
 import 'dart:async';
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ skipping 2649 matching lines @@
   V m(K a);
 }
 abstract class B<T1, T2> extends A<T2, T1> {
 }
 class C implements B<int, String> {
   int m(String a) {}
 }
 ''');
   }
 
+  test_method_OK_single_private_linkThroughOtherLibraryOfCycle() async {
+    String path = _p('/other.dart');
+    provider.newFile(
+        path,
+        r'''
+import 'test.dart';
+class B extends A2 {}
+''');
+    var library = await _encodeDecodeLibrary(r'''
+import 'other.dart';
+class A1 {
+  int _foo() => 1;
+}
+class A2 extends A1 {
+  _foo() => 2;
+}
+''');
+    checkElementText(
+        library,
+        r'''
+import 'other.dart';
+class A1 {
+  int _foo() {}
+}
+class A2 extends A1 {
+  int _foo() {}
+}
+''');
+  }
+
   test_method_OK_single_withExtends_notGeneric() async {
     var library = await _encodeDecodeLibrary(r'''
 class A {
   String m(int a) {}
 }
 class B extends Object with A {
   m(a) {}
 }
 ''');
     checkElementText(
@@ skipping 65 matching lines @@
 
   Future<LibraryElement> _encodeDecodeLibrary(String text) async {
     String path = _p('/test.dart');
     provider.newFile(path, text);
     UnitElementResult result = await driver.getUnitElement(path);
     return result.element.library;
   }
 
   String _p(String path) => provider.convertPath(path);
 }