Generative constructor factories for native objects

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
index 754e5aa0bad1b1481b6868da298300901da924c3..cb6890e1a71bca368bd819c92e49e2f425584875 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
@@ -477,9 +477,11 @@ class JavaScriptBackend extends Backend {
   }
 
   bool isInterceptedMethod(Element element) {
-    return element.isInstanceMember()
-        && !element.isGenerativeConstructorBody()
-        && interceptedElements[element.name] != null;
+    if (!element.isInstanceMember()) return false;
+    if (element.isGenerativeConstructorBody()) {
+      return Elements.isNativeOrExtendsNative(element.getEnclosingClass());
+    }
+    return interceptedElements[element.name] != null;
   }
 
   bool fieldHasInterceptedGetter(Element element) {