Substitute types in generic superclasses and interfaces.

sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
index 8466c633060bb2fb8bd425252a7ed1a76358e604..b8c46e9590cd0702c2fecb8f3f1d84dea43dd926 100644
--- a/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
@@ -354,11 +354,15 @@ class ClassEmitter extends CodeEmitterHelper {
       if (!backend.isNeededForReflection(classElement)) {
         buffer.write(',$n$n"+$reflectionName": 0');
       } else {
-        List<int> interfaces = <int>[];
+        List<int> types = <int>[];
+        if (classElement.supertype != null) {
+          types.add(
+              task.metadataEmitter.reifyType(classElement.supertype));
+        }
         for (DartType interface in classElement.interfaces) {
-          interfaces.add(task.metadataEmitter.reifyType(interface));
+          types.add(task.metadataEmitter.reifyType(interface));
         }
-        buffer.write(',$n$n"+$reflectionName": $interfaces');
+        buffer.write(',$n$n"+$reflectionName": $types');
       }
     }
   }