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Instead of relying on a compositor to do the work, we simply
wait for VBLANK and hope that the update finishes soon enough.

* doc/lispref/frames.texi (Management Parameters): Document that
frame synchronization is now supported on Haiku.

* src/haiku_support.cc (class EmacsView): New field
`use_frame_synchronization'.
(FlipBuffers): Wait for vertical blanking period.
(be_set_use_frame_synchronization): New function.
* src/haiku_support.h: Update prototypes.
* src/haikufns.c (haiku_create_frame): Set
`use-frame-synchronization'.

(haiku_set_use_frame_synchronization)
(haiku_frame_parm_handlers): New param handler.