Extract OrderedTypeSetBuilderBase from OrderedTypeSetBuilder

pkg/compiler/lib/src/closure.dart

Index: pkg/compiler/lib/src/closure.dart
diff --git a/pkg/compiler/lib/src/closure.dart b/pkg/compiler/lib/src/closure.dart
index d2998071866ccac6bc9f56f20b587e8c34bc7098..aae57e5db4236d033e40636e6af7daa22d8ba2f1 100644
--- a/pkg/compiler/lib/src/closure.dart
+++ b/pkg/compiler/lib/src/closure.dart
@@ -198,8 +198,8 @@ class ClosureFieldElement extends ElementX
 // TODO(ahe): These classes continuously cause problems.  We need to find
 // a more general solution.
 class ClosureClassElement extends ClassElementX {
-  ResolutionDartType rawType;
-  ResolutionDartType thisType;
+  ResolutionInterfaceType rawType;
+  ResolutionInterfaceType thisType;
   ResolutionFunctionType callType;
 
   /// Node that corresponds to this closure, used for source position.