HTMLImageElement shouldn't be considered broken once a load task is ongoing.
Clean-up some legacy nsImageLoadingContent state tracking while at it:
-
mLoading was not used to set ElementState anymore, and was only
checked on the "loading" attribute handling, in what seems to be a
poor man's way of preventing lazy loading to start once an image load
is ongoing? However that should already be covered by the image load
not being sync and checking mLazyLoad itself. -
The depth tracking was unneeded, image notifications have been all
async for ages.
Move some bools into nsImageLoadingContent to pack it better.
Differential Revision: https://phabricator.services.mozilla.com/D218971
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1912115
gecko-commit: cc62b982b21324e9581ab19bf8154c0072af44b1
gecko-reviewers: smaug