Handle type variables.

pkg/front_end/lib/src/fasta/builder/mixin_application_builder.dart

Index: pkg/front_end/lib/src/fasta/builder/mixin_application_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/builder/mixin_application_builder.dart b/pkg/front_end/lib/src/fasta/builder/mixin_application_builder.dart
index 86c3b2d6917c95d2ce4edea1e5a6279e85090432..6f6cbb79ec038c5e70bfb65508d88fe13e988a5d 100644
--- a/pkg/front_end/lib/src/fasta/builder/mixin_application_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/mixin_application_builder.dart
@@ -4,8 +4,12 @@
 
 library fasta.mixin_application_builder;
 
+import '../errors.dart' show
+    internalError;
+
 import 'builder.dart' show
-    TypeBuilder;
+    TypeBuilder,
+    TypeDeclarationBuilder;
 
 import 'scope.dart' show
     Scope;
@@ -17,6 +21,8 @@ abstract class MixinApplicationBuilder<T extends TypeBuilder>
 
   MixinApplicationBuilder(this.supertype, this.mixins);
 
+  String get name => null;
+
   void resolveIn(Scope scope) {
     supertype.resolveIn(scope);
     for (T t in mixins) {
@@ -24,6 +30,10 @@ abstract class MixinApplicationBuilder<T extends TypeBuilder>
     }
   }
 
+  void bind(TypeDeclarationBuilder builder) {
+    internalError("Internal error: can't bind a mixin application.");
+  }
+
   String get debugName => "MixinApplicationBuilder";
 
   StringBuffer printOn(StringBuffer buffer) {