[cairo] PDF text doesn't render

[Adrian Johnson]

This sound like this bug

https://bugs.freedesktop.org/show_bug.cgi?id=10849

There are two bugs there:
- For some reason TrueType subsetting always fails on the Mac and
   results in a CFF fallback font being embedding in the PDF.
- Mac Preview does not correctly display the CFF fonts subsetted by
   cairo.

 From the feedback I received in the bug report I know that Mac Preview 
does display CFF fonts subsetted by Adobe applications. So it is 
possible to make it work but Mac Preview is very picky about how the 
font is embedded.

The problem with fixing these is I don't have access to a Mac and fixing 
the CFF embedding problem will take a large number of iterations of:
  - change something in the PDF
  - check if it displays in Preview

Fixing the TrueType embedding problem shouldn't be hard. It just needs 
someone on a Mac to step though a debugger or use printfs to find out 
where in the code it is failing.