Language Detector: Reject when called with aborted signal

Rejects the promise returned by AILanguageDetector.detect() when the
signal passed in is already aborted.

Bug: 391713293
Change-Id: Icbeb5648458397e92fa7ec0ba8e14fd31ddd1754
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6210161
Commit-Queue: Nathan Memmott <[email protected]>
Reviewed-by: Jiacheng Guo <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1412982}

ai/language_detection/detector.https.tentative.any.js

@@ -5,11 +5,21 @@
 
 promise_test(async t => {
   const detector = await ai.languageDetector.create();
-  const results = await detector.detect("this string is in English");
+  const results = await detector.detect('this string is in English');
   // "en" should be highest confidence.
-  assert_equals(results[0].detectedLanguage, "en");
+  assert_equals(results[0].detectedLanguage, 'en');
   // Results should be from high to low confidence.
   for (let i = 0; i < results.length - 1; i++) {
     assert_greater_than_equal(results[i].confidence, results[i + 1].confidence);
   }
-});
+}, 'Simple AILanguageDetector.detect() call');
+
+promise_test(async t => {
+  const controller = new AbortController();
+  controller.abort();
+
+  const detector = await ai.languageDetector.create();
+  const detectPromise = await detector.detect('this string is in English');
+
+  await promise_rejects_dom(t, 'AbortError', detectPromise);
+}, 'AILanguageDetector.detect() call with an aborted signal.')