[WPT] Add WPT for BFCache eligibility with open IndexedDB transaction

This CL adds WPT to test if a page with open transaction can be restored
from BFCache or not. It's expected for it to be not supported and result
in `PRECONDITION_FAILED`. This will be turned to `PASS` after the CL
that implements the unblocking.

Bug: 1378823
Change-Id: I8be1d43badf07fa28eed894f176156a88b7b6a7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4060378
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Commit-Queue: Mingyu Lei <leimy@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1093723}

Author: lozy219

IndexedDB/back-forward-cache-open-transaction.window.js

@@ -0,0 +1,36 @@
+// META: title=BFCache support test for page with open IndexedDB transaction
+// META: script=/common/dispatcher/dispatcher.js
+// META: script=/common/utils.js
+// META: script=/html/browsers/browsing-the-web/back-forward-cache/resources/rc-helper.js
+// META: script=/html/browsers/browsing-the-web/remote-context-helper/resources/remote-context-helper.js
+
+'use strict';
+
+promise_test(async t => {
+  const rcHelper = new RemoteContextHelper();
+
+  // Open a window with noopener so that BFCache will work.
+  const rc1 = await rcHelper.addWindow(
+      /*config=*/ null, /*options=*/ {features: 'noopener'});
+
+  await rc1.executeScript(() => {
+    // Create an IndexedDB database and the object store named `store` as the
+    // test scope for the transaction later on.
+    const db = indexedDB.open(/*name=*/ 'test_idb', /*version=*/ 1);
+    db.onupgradeneeded = () => {
+      db.result.createObjectStore('store');
+    };
+    addEventListener('pagehide', () => {
+      let transaction = db.result.transaction(['store'], 'readwrite');
+      let store = transaction.objectStore('store');
+      store.put("key", "value");
+
+      // Queue a request to close the connection, while keeping the transaction
+      // open, so that the BFCache eligibility will be determined solely by the
+      // pending transaction.
+      db.result.close();
+    });
+  });
+
+  await assertBFCache(rc1, /*shouldRestoreFromBFCache=*/ true);
+});