Summary: 'font-synthesis: small-caps' allows the UA to synthesize
a small-caps variant when this is not supported by a font face.
We have done this by default until now, so the new feature is that
you can now turn that off with a 'font-synthesis' value that
excludes the 'small-caps' keyword.
Bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=1706080
Standard:
https://drafts.csswg.org/css-fonts/#propdef-font-synthesis
Platform coverage: all
Preference: layout.css.font-synthesis-small-caps.enabled
Other browsers: Safari supports 'font-synthesis: small-caps'.
Chrome doesn't seem to support the 'font-synthesis' property
at all.
Web Platform Tests: added in the patch
/Mats