Broken on Latest Chrome Version - Using Deprecated Functions

[darksidelemm]

It appears that the tracker is using some functions which have recently become deprecated in the latest version of Chrome ( 85.0.4183.83 ).
This results in many features of the tracker being broken, such as:

• Payload list on the left not loading.
• Buttons at the top right don't work.

The tracker is effectively un-usable at the moment because of this.

Example of the errors produced here: https://imgur.com/a/2psW6Gi

[darksidelemm]

It looks like the issue may be related to ApplicationCache being deprecated and removed in Chrome v85. It looks like Firefox will drop support too.

https://www.chromestatus.com/features/6192449487634432

[darksidelemm]

OK the issue is definitely due to the ApplicationCache deprecation.

window.applicationCache is now undefined, which was resulting in a lot of app.js breaking (in particular at the cache.addEventListener calls, with many variables and functions ending up undefined.

Commenting out those addEventListener lines results in the rest of the page loading, though I'm unsure what impact the lack of the applicationCache has on the site.

I've got a branch which has these commented out lines here: https://github.com/darksidelemm/habitat-mobile-tracker/tree/fix_chrome_85
(Note that this was based on my hide_horizon branch, so includes the horizon ring hiding fixes.