The predicate for whether browser-pane can be used on a specified screen.
The function browser-pane-available-p
returns true if there is a browser-pane implementation for the library associated with
screen-spec
.
If screen-spec is not supplied, the default library is used.
If screen-spec is supplied, it must be a valid argument to convert-to-screen.
CAPI User Guide and Reference Manual (Macintosh version) - 3 Aug 2017