Firefox testing - offscreen surfaces and OMTC

[Kevin Kofler]

Martin Stransky wrote:
> If you mean OMTC by "this" then you're right - it works fine on nightly
> because nightly is built with in-tree cairo. Fedora it built with system
> cairo which causes crashes with OMTC enabled. First build which supports
> in-tree cairo & Gtk3 is FF41.

Yet another bundled library?! Sigh!

This needs to be made to work with the system Cairo!

        Kevin Kofler