This was used to share the common implementation with the chromium port, but now that only freetype based ports use it, it can be removed and use hb_ft_face_create_cached() instead. We don't need the glyph cache either, since we are already caching glyphs in Font.
Created attachment 357047 [details] Patch
I wrote this patch on top of patch attached to bug #192151
Comment on attachment 357047 [details] Patch Probably goes without saying, but you should see if Myles has comments before landing this.
Committed r239101: <https://trac.webkit.org/changeset/239101>
<rdar://problem/46655797>
Reopening. I rolled this out in r239122 because it depends on bug #192151.
Created attachment 357219 [details] Patch for landing
Committed r239157: <https://trac.webkit.org/changeset/239157>