| Index: pkg/compiler/lib/src/js_backend/js_interop_analysis.dart
 | 
| diff --git a/pkg/compiler/lib/src/js_backend/js_interop_analysis.dart b/pkg/compiler/lib/src/js_backend/js_interop_analysis.dart
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| index 74b10ab511600fe899bc3c788862d1adac4e3a5e..da89b34344692aaae40b30318508edbea62755d5 100644
 | 
| --- a/pkg/compiler/lib/src/js_backend/js_interop_analysis.dart
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| +++ b/pkg/compiler/lib/src/js_backend/js_interop_analysis.dart
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| @@ -116,7 +116,7 @@ class JsInteropAnalysis {
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|  
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|        // Skip classes that are completely unreachable. This should only happen
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|        // when all of jsinterop types are unreachable from main.
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| -      if (!backend.compiler.world.isImplemented(classElement)) return;
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| +      if (!backend.compiler.closedWorld.isImplemented(classElement)) return;
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|  
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|        if (!classElement.implementsInterface(helpers.jsJavaScriptObjectClass)) {
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|          backend.reporter.reportErrorMessage(classElement,
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| 
 |