A bit of element model cleanup.

sdk/lib/_internal/compiler/implementation/closure.dart

 // Copyright (c) 2012, 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 closureToClassMapper;
 
 import "elements/elements.dart";
 import "dart2jslib.dart";
 import "dart_types.dart";
 import "js_backend/js_backend.dart" show JavaScriptBackend;
@@ skipping 626 matching lines @@
         if (arguments != null) {
           visit(arguments);
         }
       } else {
         visit(definition);
       }
     }
   }
 
   visitTypeAnnotation(TypeAnnotation node) {
-    Element member = executableContext.enclosingMember;
+    MemberElement member = executableContext.memberContext;
     DartType type = elements.getType(node);
     // TODO(karlklose,johnniwinther): if the type is null, the annotation is
     // from a parameter which has been analyzed before the method has been
     // resolved and the result has been thrown away.
     if (compiler.enableTypeAssertions && type != null &&
         type.containsTypeVariables) {
       if (insideClosure && member.isFactoryConstructor) {
         // This is a closure in a factory constructor.  Since there is no
         // [:this:], we have to mark the type arguments as free variables to
         // capture them in the closure.
@@ skipping 366 matching lines @@
 
   String get name => typeVariable.name;
 
   int get hashCode => typeVariable.hashCode;
 
   bool operator ==(other) {
     if (other is! TypeVariableLocal) return false;
     return typeVariable == other.typeVariable;
   }
 }