Add debugging reject values for the Storage Access API

This is reflected in the latest version of the spec, merged by privacycg/storage-access#118 .

Differential Revision: https://phabricator.services.mozilla.com/D158692

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1779575
gecko-commit: 4a2fa09ac7c8c56b8430418e56001b777be5b454
gecko-reviewers: anti-tracking-reviewers, smaug, timhuang

storage-access-api/requestStorageAccess.sub.window.js

@@ -33,10 +33,9 @@ test(() => {
 }, "[" + testPrefix + "] document.requestStorageAccess() should be supported on the document interface");
 
 promise_test(t => {
- return promise_rejects_exactly(
- t, undefined, document.requestStorageAccess(),
+ return promise_rejects_dom(t, "NotAllowedError", document.requestStorageAccess(),
  "document.requestStorageAccess() call without user gesture");
-}, "[" + testPrefix + "] document.requestStorageAccess() should be rejected by default with no user gesture");
+}, "[" + testPrefix + "] document.requestStorageAccess() should be rejected with a NotAllowedError by default with no user gesture");
 
 // Logic to load test cases within combinations of iFrames.
 if (topLevelDocument) {