Add a damage region to struct weston_renderbuffer and use it to replace
the previous_damage tracking in the drm backend.
Keep renderbuffers on a list in struct pixman_output_state and use it
to accumulate damage on all renderbuffers during repaint_output.
Now renderbuffers have to be created when pixman output state already
exists.
Reorder renderer output state and renderbuffer creation accordingly.
With this, pixman_renderer_output_set_hw_extra_damage() can be removed.
This can not yet replace the external damage tracking in the VNC
backend, which needsto know the accumulated damage that is not returned
from repaint_output.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
4d96635a3f