interceptedNames should include all interceptor method generated, not just the ones called.

dart/tests/lib/mirrors/is_odd_test.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.
+
+/// Test that otherwise unused intercepted methods are reified correctly.  This
+/// was a bug in dart2js.
+library test.is_odd_test;
+
+import 'dart:mirrors';
+
+import 'package:expect/expect.dart';
+
+main() {
+  Expect.isTrue(reflect(1).getField(new Symbol('isOdd')).reflectee);
+  Expect.isFalse(reflect(2).getField(new Symbol('isOdd')).reflectee);
+}