See T148998#4233426.

In T148998#4233426, @Krinkle wrote:

When disabling cookies in Chrome and viewing a page, I do not get any uncaught exception or error in the console from mw.storage.

However, I do see the following:

Exception in store-localstorage-init:
> DOMException: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.

This is not an error, and not from mw.storage. It is from mw.loader, and is logged as a warning (not an error) because it was caught and handled accordingly.

Perhaps we should suppress this particular warning, but in terms of behaviour and functionality, everything is working fine today.

When working with localStorage, the standard method is a try/catch. The code in question from mw.loader already does this:

mw.loader.store

try {
	raw = localStorage.getItem( mw.loader.store.getStoreKey() );
	// ..
) {
	mw.track( 'resourceloader.exception', { exception: e, source: 'store-localstorage-init' } );
}

We are currently intentionally logging it for debug purposes.

Shall we remove it?