Add a test validating that restore from invalid size can be cancelled

According the specification [1], page can prevent canvas restoration by
doing `event.preventDefault()`, in the oncontextlost callback. This CL
adds a web test validating that this works when restoring from an
invalid canvas size.

[1]: https://html.spec.whatwg.org/multipage/webappapis.html#context-lost-steps

Bug: 404257881
Change-Id: If8bf9e17a06da2f0d8c311f1c944cf61e472fbc8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6414176
Reviewed-by: Colin Blundell <blundell@chromium.org>
Commit-Queue: Jean-Philippe Gravel <jpgravel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1441272}