Besides making general sense, as far as I can tell, this patch should also prevent *one* source of `Uncaught (in promise) ...` exceptions.
Unfortunately `reason instanceof AbortError` doesn't work here, since `AbortError` isn't actually defined in browsers; note how even the DOM specification contains an example using the `name` property: https://dom.spec.whatwg.org/#aborting-ongoing-activities
This patch prevents the following errors from being logged in the console, when the unit-tests are running:
- Firefox: `Uncaught (in promise) DOMException: The operation was aborted.`
- Chrome: `Uncaught (in promise) DOMException: The user aborted a request.`
1b720a4b23