Flatten inferrer implementation

pkg/compiler/lib/src/inferrer/closure_tracer.dart

 // Copyright (c) 2013, 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 compiler.src.inferrer.closure_tracer;
 
 import '../common/names.dart' show Names;
 import '../elements/elements.dart';
 import '../js_backend/backend_helpers.dart';
 import '../types/types.dart' show TypeMask;
 import '../universe/selector.dart' show Selector;
 import 'debug.dart' as debug;
+import 'inferrer_engine.dart';
 import 'node_tracer.dart';
 import 'type_graph_nodes.dart';
 
-class ClosureTracerVisitor extends TracerVisitor<ApplyableTypeInformation> {
+class ClosureTracerVisitor extends TracerVisitor {
   final Iterable<FunctionElement> tracedElements;
   final List<CallSiteTypeInformation> _callsToAnalyze =
       new List<CallSiteTypeInformation>();
 
-  ClosureTracerVisitor(this.tracedElements, tracedType, inferrer)
+  ClosureTracerVisitor(this.tracedElements, ApplyableTypeInformation tracedType,
+      InferrerEngine inferrer)
       : super(tracedType, inferrer);
 
+  ApplyableTypeInformation get tracedType => super.tracedType;
+
   void run() {
     analyze();
     if (!continueAnalyzing) return;
     _callsToAnalyze.forEach(_analyzeCall);
     for (FunctionElement e in tracedElements) {
       e.functionSignature.forEachParameter((Element parameter) {
         ElementTypeInformation info =
             inferrer.types.getInferredTypeOf(parameter);
         info.disableInferenceForClosures = false;
       });
@@ skipping 92 matching lines @@
   @override
   visitStaticCallSiteTypeInformation(StaticCallSiteTypeInformation info) {
     super.visitStaticCallSiteTypeInformation(info);
     if (info.calledElement == tracedElements.first &&
         info.selector != null &&
         info.selector.isGetter) {
       addNewEscapeInformation(info);
     }
   }
 }