Add cogl_texture_pixmap_x11_new_left() and
cogl_texture_pixmap_x11_new_right() (which takes the left texture
as an argument) for texture pixmap rendering with stereo content.
The underlying GLXPixmap is created using a stereo visual and shared
between the left and right textures.
Reviewed-by: Robert Bragg <robert.bragg@intel.com>
4d8771a8c2