Update synchronous-callback-skipped-before-run.html to handle the DOM exception.

Per spec, if the phase of this view transition is not Done, we should
have an "AbortError" DOMException when skipping the view transition.

Also, we should avoid changing the style of `div` to make sure the test
log is rendered correctly.

Differential Revision: https://phabricator.services.mozilla.com/D239673

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1950517
gecko-commit: e793a94fab1a4827e0549a57bfa501e5a5494e36
gecko-reviewers: view-transitions-reviewers, emilio

Author: BorisChiou

css/css-view-transitions/synchronous-callback-skipped-before-run.html

@@ -8,7 +8,7 @@
 <script src="/resources/testharnessreport.js"></script>
 
 <style>
-div {
+#first {
   width: 100px;
   height: 100px;
   background: blue;
@@ -26,6 +26,10 @@
       first.style.viewTransitionName = "target";
     });
     transition.skipTransition();
+    // The phase of |transition| is not done, so skip the view transition with
+    // an "AbortError" DOMException.
+    // https://drafts.csswg.org/css-view-transitions-1/#ViewTransition-skipTransition
+    await promise_rejects_dom(t, "AbortError", transition.ready);
     await transition.finished;
 
     if (window.getComputedStyle(first).viewTransitionName == "target")