Make TypedefMirror a direct descendant of TypeMirror.

runtime/lib/mirrors_impl.dart

Index: runtime/lib/mirrors_impl.dart
diff --git a/runtime/lib/mirrors_impl.dart b/runtime/lib/mirrors_impl.dart
index e20aa8874d603d414c29eaca193a54e8a4bcd9d7..8ebba3127eaf75aff814b8cbb11cdb233c8164a0 100644
--- a/runtime/lib/mirrors_impl.dart
+++ b/runtime/lib/mirrors_impl.dart
@@ -269,7 +269,7 @@ class _LocalInstanceMirrorImpl extends _LocalObjectMirrorImpl
     if (_type == null) {
       // Note it not safe to use reflectee.runtimeType because runtimeType may
       // be overridden.
-      _type = _Mirrors._reflectType(_computeType(reflectee));
+      _type = reflectType(_computeType(reflectee));
     }
     return _type;
   }
@@ -498,7 +498,7 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
         // Object has no superclass.
         return null;
       }
-      _trueSuperclassField = _Mirrors._reflectType(supertype);
+      _trueSuperclassField = reflectType(supertype);
     }
     return _trueSuperclassField;
   }
@@ -510,7 +510,7 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
   List<ClassMirror> get superinterfaces {
     if (_superinterfaces == null) {
       _superinterfaces = _interfaces(_reflectee)
-          .map((i) => _Mirrors._reflectType(i)).toList(growable:false);
+          .map((i) => reflectType(i)).toList(growable:false);
     }
     return _superinterfaces;
   }
@@ -539,7 +539,7 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
           // The reflectee is not a mixin application.
           _mixin = this;
         } else {
-          _mixin = _Mirrors._reflectType(mixinType);
+          _mixin = reflectType(mixinType);
         }
       }
     }
@@ -761,7 +761,7 @@ class _LocalFunctionTypeMirrorImpl extends _LocalClassMirrorImpl
   TypeMirror get returnType {
     if (_returnType == null) {
       _returnType =
-          _Mirrors._reflectType(_FunctionTypeMirror_return_type(_reflectee));
+          reflectType(_FunctionTypeMirror_return_type(_reflectee));
     }
     return _returnType;
   }
@@ -847,8 +847,7 @@ class _LocalTypeVariableMirrorImpl extends _LocalDeclarationMirrorImpl
   TypeMirror _upperBound = null;
   TypeMirror get upperBound {
     if (_upperBound == null) {
-      _upperBound =
-          _Mirrors._reflectType(_TypeVariableMirror_upper_bound(_reflectee));
+      _upperBound = reflectType(_TypeVariableMirror_upper_bound(_reflectee));
     }
     return _upperBound;
   }
@@ -945,6 +944,14 @@ class _LocalLibraryMirrorImpl extends _LocalObjectMirrorImpl
     return _members;
   }
 
+  Map<Symbol, ClassMirror> _types;
+  Map<Symbol, TypeMirror> get types {
+    if (_types == null) {
+      _types = _filterMap(members, (key, value) => (value is TypeMirror));
+    }
+    return _types;
+  }
+
   Map<Symbol, ClassMirror> _classes;
   Map<Symbol, ClassMirror> get classes {
     if (_classes == null) {
@@ -1071,8 +1078,7 @@ class _LocalMethodMirrorImpl extends _LocalDeclarationMirrorImpl
       if (isConstructor) {
         _returnType = owner;
       } else {
-        _returnType =
-            _Mirrors._reflectType(_MethodMirror_return_type(_reflectee));
+        _returnType = reflectType(_MethodMirror_return_type(_reflectee));
       }
     }
     return _returnType;
@@ -1167,7 +1173,7 @@ class _LocalVariableMirrorImpl extends _LocalDeclarationMirrorImpl
   TypeMirror _type;
   TypeMirror get type {
     if (_type == null) {
-       _type = _Mirrors._reflectType(_VariableMirror_type(_reflectee));
+       _type = reflectType(_VariableMirror_type(_reflectee));
     }
     return _type;
   }
@@ -1223,8 +1229,7 @@ class _LocalParameterMirrorImpl extends _LocalVariableMirrorImpl
   TypeMirror _type = null;
   TypeMirror get type {
     if (_type == null) {
-      _type =
-          _Mirrors._reflectType(_ParameterMirror_type(_reflectee, _position));
+      _type = reflectType(_ParameterMirror_type(_reflectee, _position));
     }
     return _type;
   }
@@ -1312,7 +1317,7 @@ class _Mirrors {
       native "Mirrors_makeLocalTypeMirror";
 
   static Expando<ClassMirror> _declarationCache = new Expando("ClassMirror");
-  static Expando<ClassMirror> _instanitationCache = new Expando("TypeMirror");
+  static Expando<TypeMirror> _instanitationCache = new Expando("TypeMirror");
 
   static ClassMirror reflectClass(Type key) {
     var classMirror = _declarationCache[key];
@@ -1326,7 +1331,7 @@ class _Mirrors {
     return classMirror;
   }
 
-  static TypeMirror _reflectType(Type key) {
+  static TypeMirror reflectType(Type key) {
     var typeMirror = _instanitationCache[key];
     if (typeMirror == null) {
       typeMirror = makeLocalTypeMirror(key);