Let the SW say which urls are accessible about sw-content-indexing HOT 1 OPEN

I think this is similar to the second proposal, where we add a 'getcontent' event to SW. The service worker would then provide the list of content it contains in a similar function to what you mentioned above.

The reason we propose returning content (in addition to the URL that views that content) is so that the browser can reason about what kind of experiences are available offline. For example, the browser could have an "offline videos" section similar to something UC browser does:

Because URLs are opaque, the browser would not be able to provide this experience without the SW telling it what content it has.

from sw-content-indexing.