| Index: pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
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| diff --git a/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart b/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
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| index 2e554e5dd8eab17d16f09747b3a8f1519bdef874..cb3fb15fc68c3ffd6f91253763ca7fdb37a70dc8 100644
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| --- a/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
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| +++ b/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
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| @@ -950,7 +950,7 @@ abstract class InferrerVisitor<T, E extends MinimalInferrerEngine<T>>
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|    T get thisType {
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|      if (_thisType != null) return _thisType;
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|      ClassElement cls = outermostElement.enclosingClass;
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| -    ClassWorld classWorld = compiler.world;
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| +    ClassWorld classWorld = compiler.closedWorld;
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|      if (classWorld.isUsedAsMixin(cls)) {
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|        return _thisType = types.nonNullSubtype(cls);
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|      } else {
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| 
 |