Fix type of NamedTypeBuilder.builder.

pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart

Index: pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
index 7ab32c15b1f0ac7ff9dee16b2985067106b4f99f..9f3a0c3f9e12246833b5c6b538a0f2d758ab3e0c 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
@@ -19,13 +19,11 @@ import 'kernel_builder.dart' show
     KernelTypeBuilder,
     NamedTypeBuilder,
     TypeBuilder,
-    TypeDeclarationBuilder,
     TypeVariableBuilder;
 
-class KernelNamedTypeBuilder extends NamedTypeBuilder<KernelTypeBuilder>
+class KernelNamedTypeBuilder
+    extends NamedTypeBuilder<KernelTypeBuilder, DartType>
     implements KernelTypeBuilder {
-  TypeDeclarationBuilder<KernelTypeBuilder, DartType> builder;
-
   KernelNamedTypeBuilder(String name, List<KernelTypeBuilder> arguments,
       int charOffset, Uri fileUri)
       : super(name, arguments, charOffset, fileUri);