Here we change FontFaceSet's records array to associate gfxUserFontEntry
pointers with FontFace pointers, rather than with nsCSSFontFaceRule
pointers. This will make it more uniform to handle both CSS-connected
and unconnected FontFace objects when rebuilding the user font entries
under UpdateRules.
These set the descriptors, but don't cause anything to update, just
like setting descriptors on an @font-face rule's style declaration
doesn't do anything yet.
We add an mDescriptors that will be used to store the descriptor values
of an unconnected FontFace object. For CSS-connected FontFace objects,
the descriptors are stored in the nsCSSFontFaceRule::mDecl.mDescriptors.
(Both of these use the same type, though, CSSFontFaceDescriptors.)
Ideally we could have the descriptors always stored on the FontFace,
and for the nsCSSFontFaceStyleDecl go and fetch them from the FontFace,
but it turned out to be impossible to ensure that a FontFace could be
created whenever a nsCSSFontFaceStyleDecl was cloned, since it needs
access to the window object to create the FontFace's promise objects!
We make gfxUserFontEntry::SetLoadState virtual so that we can hook into
changes and update FontFace::mStatus. We can't just reflect the
gfxUserFontEntry's value in FontFace::Status() since the spec has
requirements about when exactly the status is set.
Every nsCSSFontFaceRule that is used will get a FontFace object to
reflect it in the FontFaceSet. Here we add storage on the
nsCSSFontFaceRule for its FontFace, although it will be the
FontFaceSet's responsibility to set it. We also add a static
constructor function on FontFace to create one that reflects a rule.