Fetched from Chrome Web Store.
CRX ID = dlefkgcbefcjoiheimkdkkhdcejpbgda

This extension has a file that has interesting size w.r.t
FileURLLoaderFactory's mime-sniffing code. Specifically,
jquery-3.2.0.min.js file is larger than 1024 bytes. This will trigger
FileURLLoaderObserver::OnSeekComplete that we care about in our test.