No need to add "HTTP(..)" for reftests using fonts outside their directory

[Xidorn Quan]

TL;NR - You don't need to use "HTTP(..)" directive on reftests to bypass
same-origin policy, and you should not do so.


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Historically, we added "HTTP(..)", "HTTP(../..)", etc. for downloadable
fonts in reftests to bypass the strict same-origin policy of file
protocol, which bans accessing fonts outside the directory of a reftest.


The strict same-origin policy has been disabled for reftests since
Firefox 22 (bug 846890[1]), so it makes no sense to add "HTTP(..)" for
that anymore.


In addition, my experiment shows a great improvement on time consumption
of reftest tasks on debug builds by simply removing "HTTP(..)" from
reftest.list (data in bug 1258916 comment 79[2]), so adding "HTTP" for
downloadable fonts is not only useless, but also harmful.


I've landed a patch in bug 1258916[3] to remove "HTTP(..)" thing from
reftests imported from CSSWG's test repo. Bug 1318526[4] is for removing
that from existing reftests elsewhere.


- Xidorn


Links:

1. https://bugzilla.mozilla.org/show_bug.cgi?id=846890
2. https://bugzilla.mozilla.org/show_bug.cgi?id=1258916#c79
3. https://bugzilla.mozilla.org/show_bug.cgi?id=1258916#c98
4. https://bugzilla.mozilla.org/show_bug.cgi?id=1318526