Native abstract classes may be 'instantiated'

sdk/lib/_internal/compiler/implementation/enqueue.dart

Index: sdk/lib/_internal/compiler/implementation/enqueue.dart
diff --git a/sdk/lib/_internal/compiler/implementation/enqueue.dart b/sdk/lib/_internal/compiler/implementation/enqueue.dart
index e3e9e64d4f6e016fcccffbf8efc37415944dcc20..d68333a3a997d389ad62138f2fbd18ce055338e3 100644
--- a/sdk/lib/_internal/compiler/implementation/enqueue.dart
+++ b/sdk/lib/_internal/compiler/implementation/enqueue.dart
@@ -117,7 +117,12 @@ abstract class Enqueuer {
       elements.registerDependency(cls);
       cls.ensureResolved(compiler);
       universe.instantiatedTypes.add(type);
-      if (!cls.isAbstract(compiler)) {
+      if (!cls.isAbstract(compiler)
+          // We can't use the closed-world assumption with native abstract
+          // classes; a native abstract class may have non-abstract subclasses
+          // not declared to the program.  Instances of these classes are
+          // indistinguishable from the abstract class.
+          || cls.isNative()) {

[ngeoffray, 2013/09/10 11:55:37]

Could we avoid marking the native classes abstract instead?

         universe.instantiatedClasses.add(cls);
       }
       onRegisterInstantiatedClass(cls);