Remove ClassHierarchy factory constructor.

pkg/kernel/test/typecheck.dart

 // Copyright (c) 2016, 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 'package:kernel/kernel.dart';
 import 'package:kernel/class_hierarchy.dart';
 import 'package:kernel/core_types.dart';
+import 'package:kernel/src/incremental_class_hierarchy.dart';
 import 'package:kernel/type_checker.dart';
 import 'dart:io';
 
 final String usage = '''
 Usage: typecheck FILE.dill
 
 Runs the strong mode type checker on the given program.
 ''';
 
 main(List<String> args) {
   if (args.length != 1) {
     print(usage);
     exit(1);
   }
   var program = loadProgramFromBinary(args[0]);
   var coreTypes = new CoreTypes(program);
-  var hierarchy = new ClassHierarchy(program);
+  var hierarchy = new IncrementalClassHierarchy();
   new TestTypeChecker(coreTypes, hierarchy).checkProgram(program);
 }
 
 class TestTypeChecker extends TypeChecker {
   TestTypeChecker(CoreTypes coreTypes, ClassHierarchy hierarchy)
       : super(coreTypes, hierarchy);
 
   @override
   void checkAssignable(TreeNode where, DartType from, DartType to) {
     if (!environment.isSubtypeOf(from, to)) {
       fail(where, '$from is not a subtype of $to');
     }
   }
 
   @override
   void fail(TreeNode where, String message) {
     Location location = where.location;
     String locationString = location == null ? '' : '($location)';
     print('[error] $message $locationString');
   }
 }