IndexedDB offers two durability modes for readwrite transactions: `relaxed` and `strict`. This may be specified via the optional `options` struct when creating a transaction. See https://developer.mozilla.org/en-US/docs/Web/API/IDBDatabase/transaction for more details. If not specified, the current default in Chromium is `strict`. Due to performance considerations, we plan to change the default to `relaxed`, which also aligns Chromium with FireFox and Safari. Blog post: https://developer.chrome.com/blog/indexeddb-durability-mode-now-defaults-to-relaxed