Remove ClassHierarchy factory constructor.

KernelTarget already uses IncrementalClassHierarchy, and other clients
either need ClosedWorldClassHierarchy, so should explicitly create it,
or don't care, and can be switched to IncrementalClassHierarchy.

R=ahe@google.com, kmillikin@google.com, paulberry@google.com, sigmund@google.com
BUG=

Review-Url: https://codereview.chromium.org/2930973002 .

pkg/front_end/test/fasta/type_inference/type_constraint_gatherer_test.dart

@@ -6,8 +6,8 @@ import 'package:front_end/src/fasta/type_inference/type_constraint_gatherer.dart
 import 'package:front_end/src/fasta/type_inference/type_schema.dart';
 import 'package:front_end/src/fasta/type_inference/type_schema_environment.dart';
 import 'package:kernel/ast.dart';
-import 'package:kernel/class_hierarchy.dart';
 import 'package:kernel/core_types.dart';
+import 'package:kernel/src/incremental_class_hierarchy.dart';
 import 'package:kernel/testing/mock_sdk_program.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -209,8 +209,8 @@ class TypeConstraintGathererTest {
 
   void _checkConstraints(
       DartType a, DartType b, List<String> expectedConstraints) {
-    var typeSchemaEnvironment =
-        new TypeSchemaEnvironment(coreTypes, new ClassHierarchy(program), true);
+    var typeSchemaEnvironment = new TypeSchemaEnvironment(
+        coreTypes, new IncrementalClassHierarchy(), true);
     var typeConstraintGatherer = new TypeConstraintGatherer(
         typeSchemaEnvironment, [T1.parameter, T2.parameter]);
     var constraints = typeConstraintGatherer.trySubtypeMatch(a, b)

pkg/front_end/test/fasta/type_inference/type_schema_environment_test.dart

@@ -5,8 +5,8 @@
 import 'package:front_end/src/fasta/type_inference/type_schema.dart';
 import 'package:front_end/src/fasta/type_inference/type_schema_environment.dart';
 import 'package:kernel/ast.dart';
-import 'package:kernel/class_hierarchy.dart';
 import 'package:kernel/core_types.dart';
+import 'package:kernel/src/incremental_class_hierarchy.dart';
 import 'package:kernel/testing/mock_sdk_program.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -802,7 +802,7 @@ class TypeSchemaEnvironmentTest {
 
   TypeSchemaEnvironment _makeEnv() {
     return new TypeSchemaEnvironment(
-        coreTypes, new ClassHierarchy(program), true);
+        coreTypes, new IncrementalClassHierarchy(), true);
   }
 
   DartType _map(DartType key, DartType value) =>

pkg/kernel/lib/class_hierarchy.dart

@@ -13,9 +13,6 @@ import 'type_algebra.dart';
 /// TODO(scheglov) Several methods are not used, or used only in tests.
 /// Check if these methods are not useful and should be removed .
 abstract class ClassHierarchy {
-  factory ClassHierarchy(Program program) =>
-      new ClosedWorldClassHierarchy(program);
-
   /// Given the [unordered] classes, return them in such order that classes
   /// occur after their superclasses.  If some superclasses are not in
   /// [unordered], they are not included.

pkg/kernel/test/class_hierarchy_bench.dart

@@ -41,7 +41,7 @@ main(List<String> args) {
   ClassHierarchy buildHierarchy() {
     return options['basic']
         ? new BasicClassHierarchy(program)
-        : new ClassHierarchy(program);
+        : new ClosedWorldClassHierarchy(program);
   }
 
   var watch = new Stopwatch()..start();

pkg/kernel/test/treeshaker_bench.dart

@@ -50,7 +50,7 @@ void main(List<String> args) {
   ClassHierarchy buildClassHierarchy() {
     return options['basic']
         ? new BasicClassHierarchy(program)
-        : new ClassHierarchy(program);
+        : new ClosedWorldClassHierarchy(program);
   }
 
   CoreTypes coreTypes = new CoreTypes(program);

pkg/kernel/test/treeshaker_membench.dart

@@ -39,7 +39,7 @@ main(List<String> args) {
   bool strongMode = options['strong'];
 
   Program program = loadProgramFromBinary(filename);
-  ClassHierarchy hierarchy = new ClassHierarchy(program);
+  ClassHierarchy hierarchy = new ClosedWorldClassHierarchy(program);
   CoreTypes coreTypes = new CoreTypes(program);
 
   int copyCount = int.parse(options['count']);

pkg/kernel/test/type_subtype_test.dart

@@ -2,6 +2,7 @@
 // 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/src/incremental_class_hierarchy.dart';
 import 'package:test/test.dart';
 import 'package:kernel/ast.dart';
 import 'package:kernel/class_hierarchy.dart';
@@ -171,8 +172,7 @@ MockSubtypeTester makeSubtypeTester(Map<String, List<String>> testcase) {
       }
     }
   }
-  var program = new Program(libraries: [environment.dummyLibrary]);
-  var hierarchy = new ClassHierarchy(program);
+  var hierarchy = new IncrementalClassHierarchy();
   return new MockSubtypeTester(hierarchy, objectClass.rawType,
       functionClass.rawType, futureClass, futureOrClass, environment);
 }

pkg/kernel/test/typecheck.dart

@@ -4,6 +4,7 @@
 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';
 
@@ -20,7 +21,7 @@ main(List<String> args) {
   }
   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);
 }