Compute bounds of type variables.

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

Index: pkg/front_end/lib/src/fasta/builder/library_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/builder/library_builder.dart b/pkg/front_end/lib/src/fasta/builder/library_builder.dart
index 2fb52ae277ad3faaaa1211e1be93830799927246..d163b8c5be333ae21ff2de288c5d1b3125ba1ec6 100644
--- a/pkg/front_end/lib/src/fasta/builder/library_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/library_builder.dart
@@ -18,6 +18,7 @@ import '../loader.dart' show
 
 import 'builder.dart' show
     Builder,
+    ClassBuilder,
     InvalidTypeBuilder,
     TypeBuilder;
 
@@ -69,4 +70,6 @@ abstract class LibraryBuilder<T extends TypeBuilder, R> extends Builder {
       String name, Builder builder, Builder other, int charOffset);
 
   int finishStaticInvocations() => 0;
+
+  int finishTypeVariables(ClassBuilder object) => 0;
 }