third_party/blink/web_tests/bindings/webidl-operation-functions-should-have-no-prototype.html - chromium/src - Git at Google

 <!DOCTYPE html>
 <script src="../resources/testharness.js"></script>
 <script src="../resources/testharnessreport.js"></script>
 <script>
 test(() => {
   assert_false("prototype" in document.appendChild,
                "WebIDL operation functions should not have a prototype property.");
 });
 </script>
	<!DOCTYPE html>
	<script src="../resources/testharness.js"></script>
	<script src="../resources/testharnessreport.js"></script>
	<script>
	test(() => {
	assert_false("prototype" in document.appendChild,
	"WebIDL operation functions should not have a prototype property.");
	});
	</script>