Align IndexedDB metadata rollback on transaction abort to spec.

third_party/WebKit/LayoutTests/storage/indexeddb/resources/rename-common.js

Index: third_party/WebKit/LayoutTests/storage/indexeddb/resources/rename-common.js
diff --git a/third_party/WebKit/LayoutTests/storage/indexeddb/resources/rename-common.js b/third_party/WebKit/LayoutTests/storage/indexeddb/resources/rename-common.js
index ac3ff5996e7fd997387b0811f51f863d1f8d1515..c24a9fb92bd2c30d08a428086a72a6f3d7549b5b 100644
--- a/third_party/WebKit/LayoutTests/storage/indexeddb/resources/rename-common.js
+++ b/third_party/WebKit/LayoutTests/storage/indexeddb/resources/rename-common.js
@@ -75,6 +75,19 @@ const createDatabase = (testCase, setupCallback) => {
         migrateDatabase(testCase, 1, setupCallback));
 };
 
+// Opens an IndexedDB database without performing schema changes.
+//
+// The given version number must match the database's current version.
+//
+// Returns a promise that resolves to an IndexedDB database. The caller must
+// close the database.
+const openDatabase = (testCase, version) => {
+    const request = indexedDB.open(databaseName(testCase), version);
+    const eventWatcher = requestWatcher(testCase, request);
+    return eventWatcher.wait_for('success').then(
+        event => event.target.result);
+}
+
 // The data in the 'books' object store records in the first example of the
 // IndexedDB specification.
 const BOOKS_RECORD_DATA = [