[ServiceWorker] Receivers of ranged responses must ensure all ranges come from the same underlying resource (#703)

Say an element makes two ranged requests and receives two responses, and the serviceworker handles both. If the element accepts opaque responses (video), the serviceworker could mix opaque data from different urls, or opaque data with non-opaque data.

@sirdarckcat - could you quickly sum up an attack based on this? My brain's kinda reset and I can't think of anything bad you can do here other than lie to yourself.

+@slightlyoff 

---
Reply to this email directly or view it on GitHub:
https://github.com/slightlyoff/ServiceWorker/issues/703