CONSOLE WARNING: line 1: Application Cache API manifest selection is deprecated and will be removed in M85, around August 2020. See https://www.chromestatus.com/features/6192449487634432 for more details.
CONSOLE WARNING: line 25: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
CONSOLE WARNING: Application Cache API use is deprecated and will be removed in M85, around August 2020. See https://www.chromestatus.com/features/6192449487634432 for more details.
Test a simple offline application self-update process. Should print a series of messages followed with DONE:

Updating cache group...
Cache status is UPDATEREADY
Updating cache group once more...
Cache status is UPDATEREADY
Associating document with the newest cache version...
Cache status is IDLE
DONE