In bug 1603542 we have added a warning about preloaded resources that are not used. Lack of automated testing seems to let slip the missing warning about css styles at the time of landing the patch, or something has changed since that time.

Set release status flags based on info from the regressing bug 1603542

Is this really a regression from bug 1603542, or is this just something that was supposed to start happening as of bug 1603542 but seems to not be happening?

(I'm not entirely clear from comment 0 what the exact nature of the problem is.)

(Also, are there any testcases/demos that you can link to that demonstrate the issue?)

(In reply to Daniel Holbert [:dholbert] from comment #2)

Is this really a regression from bug 1603542, or is this just something that was supposed to start happening as of bug 1603542 but seems to not be happening?

(I'm not entirely clear from comment 0 what the exact nature of the problem is.)

The latter - it was expected to work, but it doesn't.

Not just the one that takes a channel. This fixes the issue.

Also, as an optimization, avoid creating a timer if we're used already
or we have already one.

Drive-by, but this is what a bunch of other console messages do.

Depends on D87267

https://hg.mozilla.org/mozilla-central/rev/c03de6bc2650
https://hg.mozilla.org/mozilla-central/rev/92a28b0098cf