[cairo] [Patch] cairo-trace: Fix mark-dirty with the xcb backend

[Uli Schlachter]

Hi,

today I hit yet another assertion failure with cairo. cairo-trace will hook into
cairo_surface_mark_dirty and first do some other magic before calling the real
cairo_surface_mark_dirty.
This magic, when applied to a xcb surface, causes a new snapshot to be created
in cairo-trace's mark_dirty wrapper right before the real mark_dirty is called.
This function then dies in an assert (! _cairo_surface_has_snapshots (surface));

The attached patch will simply swap the order in which cairo-trace does "its
thing". Since I didn't mess with cairo-trace's source code before, I'd be happy
if someone could take a look and tell me that I didn't break anything too badly.

Cheers,
Uli
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