A way to coordinate the refresh of all controlled windows to facilitate an upgrade

[jakearchibald]

This used to be clients.reloadAll(), which still feels like the right name, but I don't think we've thought about this enough to make it "version 1".

Here's what we had before I took out of the ts:

    // Assists in restarting all windows
    //
    // Return a new Promise
    // For each attached window:
    //   Fire onreloadpage against navigator.serviceWorker
    //   If onreloadpage has default prevented:
    //     Unfreeze any frozen windows
    //     reject returned promise
    //     abort these steps
    //   If waitUntil called on onreloadpage event:
    //     frozen windows may wish to indicate which window they're blocked on
    //     yeild until promise passed into waitUntil resolves
    //     if waitUntil promise is accepted:
    //       freeze window (ui may wish to grey it out)
    //     else:
    //       Unfreeze any frozen windows
    //       reject returned promise
    //       abort these steps
    //   Else:
    //     freeze window (ui may wish to grey it out)
    // Unload all windows
    // If any window fails to unload, eg via onbeforeunload:
    //   Unfreeze any frozen windows
    //   reject returned promise
    //   abort these steps
    // Close all connections between the old worker and windows
    // Activate the new worker
    // Reload all windows asynchronously
    // Resolve promise

@annevk pointed out that you can have a controlled SharedWorker being used by non-controlled pages. We don't have the concept of reloading a SharedWorker at the moment, so we need to overcome that.

[h2non]

+1