Introduce a testing framework for use with fasta type inference.

pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart

Index: pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart b/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
index 94984dba3ce8d1104ec2e44251fc01c7f098af17..c38c4113b3dd40b243eb39f636f19efce09fb57c 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.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.md file.
 
+import 'package:front_end/src/base/instrumentation.dart';
 import 'package:kernel/ast.dart' show DartType;
 import 'package:kernel/class_hierarchy.dart';
 import 'package:kernel/core_types.dart';
@@ -20,11 +21,13 @@ abstract class TypeInferrer<S, E, V, F> {
 
   final ClassHierarchy classHierarchy;
 
+  final Instrumentation instrumentation;
+
   /// The URI of the code for which type inference is currently being
   /// performed--this is used for testing.
   Uri uri;
 
-  TypeInferrer(this.coreTypes, this.classHierarchy);
+  TypeInferrer(this.coreTypes, this.classHierarchy, this.instrumentation);
 
   /// Performs type inference on a method with the given method [body].
   ///