WPT: Update IDB WPT helper to avoid duplicate object store creation (#…

…38102)

In the WPT that requires creating IDB connection with different version,
we should not create the same object store for multiple times. This CL adds
a version check to ensure that it's only created when version equals to 1.

Bug: 1331187
Change-Id: I4d52cc0e2c56493db5bad59705822c3550fa886c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4178503
Reviewed-by: Fergal Daly <fergal@chromium.org>
Commit-Queue: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1107329}

Co-authored-by: Mingyu Lei <leimy@chromium.org>

IndexedDB/resources/support.js

@@ -216,7 +216,10 @@ async function createIndexedDBForTesting(rc, dbName, version) {
   await rc.executeScript((dbName, version) => {
     let request = indexedDB.open(dbName, version);
     request.onupgradeneeded = () => {
-      request.result.createObjectStore('store');
+      if (version == 1) {
+        // Only create the object store once.
+        request.result.createObjectStore('store');
+      }
     }
     request.onversionchange = () => {
       fail(t, 'unexpectedly received versionchange event.');