Explore support for network-idle-callback library #2
Description
From Chrome metrics:
We don't have a platform way to expose network idle just yet, but the service worker approach should be reasonably reliable (but comes with the overhead of requiring a serviceworker, obviously).
re: https://github.com/pastelsky/network-idle-callback
If I implemented support for this, we could either do it as a default (downside: requires everyone to use Service Workers) or we make it a suggested option.