Infer only ClassElementImpl in InstanceMemberInferrer, tweaks for link.

pkg/analyzer/lib/src/task/strong_mode.dart

 // Copyright (c) 2015, 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 analyzer.src.task.strong_mode;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 55 matching lines @@
 
   /**
    * The inheritance manager used to find overridden method.
    */
   final InheritanceManager inheritanceManager;
 
   /**
    * The classes that have been visited while attempting to infer the types of
    * instance members of some base class.
    */
-  HashSet<AbstractClassElementImpl> elementsBeingInferred =
-      new HashSet<AbstractClassElementImpl>();
+  HashSet<ClassElementImpl> elementsBeingInferred =
+      new HashSet<ClassElementImpl>();
 
   /**
    * Initialize a newly create inferrer.
    */
   InstanceMemberInferrer(this.typeProvider, this.inheritanceManager,
       {TypeSystem typeSystem})
       : typeSystem = (typeSystem != null) ? typeSystem : new TypeSystemImpl();
 
   /**
    * Infer type information for all of the instance members in the given
@@ skipping 107 matching lines @@
     return matchingParameter == null
         ? typeProvider.dynamicType
         : matchingParameter.type;
   }
 
   /**
    * Infer type information for all of the instance members in the given
    * [classElement].
    */
   void _inferClass(ClassElement classElement) {
-    if (classElement is AbstractClassElementImpl) {
+    if (classElement is ClassElementImpl) {
       if (classElement.hasBeenInferred) {
         return;
       }
       if (!elementsBeingInferred.add(classElement)) {
         // We have found a circularity in the class hierarchy. For now we just
         // stop trying to infer any type information for any classes that
         // inherit from any class in the cycle. We could potentially limit the
         // algorithm to only not inferring types in the classes in the cycle,
         // but it isn't clear that the results would be significantly better.
         throw new _CycleException();
@@ skipping 255 matching lines @@
         results.add(element);
       }
     }
   }
 }
 
 /**
  * A class of exception that is not used anywhere else.
  */
 class _CycleException implements Exception {}