Currently, the OTS sanitizer doesn't know about OpenType Variations tables, and so it strips them from downloaded font resources. This makes it impossible to deploy variation fonts as webfonts, even for testing/experimental purposes. We aren't ready to enable variation-font support by default yet, but we do have it available behind a pref on macOS Sierra. So that interested people can more usefully experiment with this, I'd like to add a pref that allows the Variations tables to bypass OTS and be preserved in @font-face resources. This will allow people to try out sites such as http://www.axis-praxis.org/, which has a bunch of variation fonts for experimentation. (Eventually, we'll want to take an OTS update that understands and validates these tables, or verify that the font back-ends can handle invalid tables safely.)
Created attachment 8839214 [details] [diff] [review] Implement a pref that allows OpenType Variation tables to bypass the sanitizer, as it doesn't know about them Until these tables are implemented in OTS (bug 1341088), we should provide a pref to allow people to bypass it for testing purposes.
https://hg.mozilla.org/integration/mozilla-inbound/rev/f305383515a1f74e0c34edd81f0590d3f44c45c1 Bug 1341085 - Implement a pref that allows OpenType Variation tables to bypass the sanitizer, as it doesn't know about them. r=jrmuizel