Offline pages needs more information to know when it is time to snapshot a page. One way we can do that is to calculate the percentage of requested resources that have become available by type.
Add a system to register observers which will get notified whenever any net resource arrives or is requested, to allow the offline pages system to calculate when it is time to take an offline snapshot during the process of background loading.
Comment 1 by bugdroid1@chromium.org
, Apr 25 2017