facemenu-active-faces
facemenu-active-faces is a compiled Lisp function in `facemenu.el
'.
(facemenu-active-faces FACE-LIST &optional FRAME)
Return from FACE-LIST those faces that would be used for display.
This means each face attribute is not specified in a face earlier in FACE-LIST
and such a face is therefore active when used to display text.
If the optional argument FRAME is given, use the faces in that frame; otherwise
use the selected frame. If t, then the global, non-frame faces are used.