Mostly use Entity in InterceptorData

pkg/compiler/lib/src/common_elements.dart

 // Copyright (c) 2014, 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.
 
 // TODO(sigmund): rename and move to common/elements.dart
 library dart2js.type_system;
 
 import 'common.dart';
 import 'elements/types.dart';
 import 'elements/entities.dart';
@@ skipping 223 matching lines @@
   /// Lookup the member [name] in [cls], fail if the class is missing and
   /// [required].
   MemberEntity lookupClassMember(ClassEntity cls, String name,
       {bool setter: false, bool required: false});
 
   /// Lookup the constructor [name] in [cls], fail if the class is missing and
   /// [required].
   ConstructorEntity lookupConstructor(ClassEntity cls, String name,
       {bool required: false});
 
+  /// Calls [f] for each class member declared or inherited in [cls] together
+  /// with the class that declared the member.
+  ///
+  /// TODO(johnniwinther): This should not include static members of
+  /// superclasses.
+  void forEachClassMember(
+      ClassEntity cls, void f(ClassEntity declarer, MemberEntity member));
+
+  /// Calls [f] for each class that is mixed into [cls] or one of its
+  /// superclasses.
+  void forEachMixin(ClassEntity cls, void f(ClassEntity mixin));
+
   /// Create the instantiation of [cls] with the given [typeArguments].
   InterfaceType createInterfaceType(
       ClassEntity cls, List<DartType> typeArguments);
 
   /// Returns the 'raw type' of [cls]. That is, the instantiation of [cls]
   /// where all types arguments are `dynamic`.
   InterfaceType getRawType(ClassEntity cls);
 
   /// Returns the 'this type' of [cls]. That is, the instantiation of [cls]
   /// where the type arguments are the type variables of [cls].
@@ skipping 246 matching lines @@
   }
 
   @override
   InterfaceType streamType([DartType elementType]) {
     if (elementType == null) {
       return getRawType(streamClass);
     }
     return createInterfaceType(streamClass, [elementType]);
   }
 }