pkg/docgen: fixed type references within typedef doc comments

pkg/docgen/lib/src/models/typedef.dart

Index: pkg/docgen/lib/src/models/typedef.dart
diff --git a/pkg/docgen/lib/src/models/typedef.dart b/pkg/docgen/lib/src/models/typedef.dart
index 6d2890f2f7b106bf03f19b3642b6e217b581225b..17e4208aa906012073d01e8b3033a02feaedf821 100644
--- a/pkg/docgen/lib/src/models/typedef.dart
+++ b/pkg/docgen/lib/src/models/typedef.dart
@@ -6,8 +6,6 @@ library docgen.models.typedef;
 
 import '../exports/source_mirrors.dart';
 
-import 'package:markdown/markdown.dart' as markdown;
-
 import '../library_helpers.dart';
 
 import 'dummy_mirror.dart';
@@ -17,7 +15,7 @@ import 'generic.dart';
 import 'parameter.dart';
 import 'owned_indexable.dart';
 
-class Typedef extends OwnedIndexable {
+class Typedef extends OwnedIndexable<TypedefMirror> {
   final String returnType;
 
   final Map<String, Parameter> parameters;
@@ -61,8 +59,6 @@ class Typedef extends OwnedIndexable {
     return map;
   }
 
-  markdown.Node fixReference(String name) => owner.fixReference(name);
-
   String get typeName => 'typedef';
 
   bool isValidMirror(DeclarationMirror mirror) => mirror is TypedefMirror;