Tighten up handling of JS types and add test.

pkg/dev_compiler/lib/src/compiler/code_generator.dart

Index: pkg/dev_compiler/lib/src/compiler/code_generator.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/code_generator.dart b/pkg/dev_compiler/lib/src/compiler/code_generator.dart
index e24dce52e3e059d672b4e0ddcc8c594df115cef4..12bd4371b93bd0de779ea936b04ec875dc6021a3 100644
--- a/pkg/dev_compiler/lib/src/compiler/code_generator.dart
+++ b/pkg/dev_compiler/lib/src/compiler/code_generator.dart
@@ -437,9 +437,7 @@ class CodeGenerator extends Object
       return _jsInteropStaticMemberName(e.getter, name: e.name) ??
           _jsInteropStaticMemberName(e.setter, name: e.name);
     }
-    if (e is ExecutableElement &&
-        e.isExternal &&
-        findAnnotation(e, isPublicJSAnnotation) != null) {
+    if (e is ExecutableElement && e.isExternal) {
       return getAnnotationName(e, isPublicJSAnnotation) ?? name ?? e.name;
     }
     return null;