Implement JsMirrorSystem.libraries.

dart/tests/lib/mirrors/libraries_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.
+
+library test.libraries_test;
+
+import 'dart:mirrors';
+
+import 'package:expect/expect.dart';
+
+main() {
+  MirrorSystem mirrors = currentMirrorSystem();
+  Expect.isNotNull(mirrors, 'mirrors is null');
+
+  Map<Uri, LibraryMirror> libraries = mirrors.libraries;
+  Expect.isNotNull(libraries, 'libraries is null');
+
+  LibraryMirror mirrorsLibrary = libraries[Uri.parse('dart:mirrors')];
+  Expect.isNotNull(mirrorsLibrary, 'mirrorsLibrary is null');
+
+  print(mirrorsLibrary.classes);
+  ClassMirror cls = mirrorsLibrary.classes[const Symbol('LibraryMirror')];
+  Expect.isNotNull(cls, 'cls is null');
+
+  Expect.equals(const Symbol('dart.mirrors.LibraryMirror'), cls.qualifiedName);
+  // TODO(ahe): Enable when VM implements equality of class mirrors:
+  // Expect.equals(reflectClass(LibraryMirror), cls);
+  print(mirrorsLibrary);
+}