Expose getInterfaceMembers method through ClassHierarchy.

pkg/kernel/lib/src/incremental_class_hierarchy.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 kernel.incremental_class_hierarchy;
 
 import 'dart:collection';
 import 'dart:math';
 
 import 'package:kernel/ast.dart';
 import 'package:kernel/class_hierarchy.dart';
@@ skipping 253 matching lines @@
 
   @override
   Member getInterfaceMember(Class node, Name name, {bool setter: false}) {
     _ClassInfo info = _getInfo(node);
     List<Member> members =
         setter ? info.interfaceSetters : info.interfaceGettersAndCalls;
     return _findMemberByName(members, name);
   }
 
   @override
+  List<Member> getInterfaceMembers(Class class_, {bool setters: false}) {
+    var info = _getInfo(class_);
+    return setters ? info.interfaceSetters : info.interfaceGettersAndCalls;
+  }
+
+  @override
   Iterable<Class> getOrderedClasses(Iterable<Class> unordered) {
     unordered.forEach(_getInfo);
     var unorderedSet = unordered.toSet();
     return _info.keys.where(unorderedSet.contains);
   }
 
   @override
   List<Class> getRankedSuperclasses(Class node) {
     var info = _getInfo(node);
     return _getRankedSuperclassList(info).map((info) => info.node).toList();
@@ skipping 453 matching lines @@
 class _LubHeap extends Heap<_ClassInfo> {
   @override
   bool sortsBefore(_ClassInfo a, _ClassInfo b) => sortsBeforeStatic(a, b);
 
   static bool sortsBeforeStatic(_ClassInfo a, _ClassInfo b) {
     if (a.depth > b.depth) return true;
     if (a.depth < b.depth) return false;
     return a.id < b.id;
   }
 }