Fix missing .mirror.

pkg/docgen/lib/docgen.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.
 
 /// **docgen** is a tool for creating machine readable representations of Dart
 /// code metadata, including: classes, members, comments and annotations.
 ///
 /// docgen is run on a `.dart` file or a directory containing `.dart` files.
 ///
 ///      $ dart docgen.dart [OPTIONS] [FILE/DIR]
@@ skipping 1561 matching lines @@
     // can get for their inherited versions the comments.
     methods.forEach((qualifiedName, method) {
       if (!method.mirror.isConstructor) method.ensureCommentFor(method);
     });
   }
 
   /// If a class extends a private superclass, find the closest public
   /// superclass of the private superclass.
   String validSuperclass() {
     if (superclass == null) return 'dart.core.Object';
-    if (superclass._isVisible) return dart2js_util.qualifiedNameOf(superclass);
+    if (superclass._isVisible) {
+      return dart2js_util.qualifiedNameOf(superclass.mirror);

[Johnni Winther, 2014/01/31 19:19:45]

Maybe this should just be `return superclass.qualifiedName;`.

[floitsch, 2014/02/01 02:01:15]

Seattle (Emily and Alan) agreed to fix this.

+    }
     return superclass.validSuperclass();
   }
 
   /// Generates a map describing the [Class] object.
   Map toMap() => {
     'name': name,
     'qualifiedName': qualifiedName,
     'comment': comment,
     'isAbstract' : isAbstract,
     'superclass': validSuperclass(),
@@ skipping 398 matching lines @@
         .map((e) => originalMirror.getField(e.simpleName).reflectee)
         .where((e) => e != null)
         .toList();
   }
 
   Map toMap() => {
     'name': Indexable.getDocgenObject(mirror, owningLibrary).docName,
     'parameters': parameters
   };
 }