This commit added two APIs to support the DRI swap buffer.
one is glamor_egl_exchange_buffers() which can swap two
pixmaps' underlying KHRimages/fbos/texs. The DDX layer should
exchange the DRM bos to make them consistent to each other.
Another API is glamor_egl_create_textured_screen_ext(), which
extent one more parameters to track the DDX layer's back pixmap
pointer. This is for the triple buffer support. When using triple
buffer, the DDX layer will keep a back pixmap rather then the
front pixmap and the pixmap used by the DRI2 client. And during
the closing screen stage, we have to dereference all the back
pixmap's glamor resources. Thus we have to extent this API to
register it when create new screen.
Signed-off-by: Zhigang Gong <zhigang.gong@linux.intel.com>
213285f2b8