Migrate to kbinani/screenshot for screen adapter

https://github.com/kbinani/screenshot is a library to capture desktop
screen. It is cgo free for Windows, Linux, FreeBSD, OpenBSD, NetBSD, and
Solaris.

pkg/driver/screen/x11_linux.go

@@ -1,92 +0,0 @@
-package screen
-
-import (
-	"fmt"
-	"image"
-	"time"
-
-	"github.com/pion/mediadevices/pkg/driver"
-	"github.com/pion/mediadevices/pkg/frame"
-	"github.com/pion/mediadevices/pkg/io/video"
-	"github.com/pion/mediadevices/pkg/prop"
-)
-
-type screen struct {
-	num    int
-	reader *reader
-	tick   *time.Ticker
-}
-
-func deviceID(num int) string {
-	return fmt.Sprintf("X11Screen%d", num)
-}
-
-func init() {
-	dp, err := openDisplay()
-	if err != nil {
-		// No x11 display available.
-		return
-	}
-	defer dp.Close()
-	numScreen := dp.NumScreen()
-	for i := 0; i < numScreen; i++ {
-		driver.GetManager().Register(
-			&screen{
-				num: i,
-			},
-			driver.Info{
-				Label:      deviceID(i),
-				DeviceType: driver.Screen,
-			},
-		)
-	}
-}
-
-func (s *screen) Open() error {
-	r, err := newReader(s.num)
-	if err != nil {
-		return err
-	}
-	s.reader = r
-	return nil
-}
-
-func (s *screen) Close() error {
-	s.reader.Close()
-	if s.tick != nil {
-		s.tick.Stop()
-	}
-	return nil
-}
-
-func (s *screen) VideoRecord(p prop.Media) (video.Reader, error) {
-	if p.FrameRate == 0 {
-		p.FrameRate = 10
-	}
-	s.tick = time.NewTicker(time.Duration(float32(time.Second) / p.FrameRate))
-
-	var dst image.RGBA
-	reader := s.reader
-
-	r := video.ReaderFunc(func() (image.Image, func(), error) {
-		<-s.tick.C
-		return reader.Read().ToRGBA(&dst), func() {}, nil
-	})
-	return r, nil
-}
-
-func (s *screen) Properties() []prop.Media {
-	rect := s.reader.img.Bounds()
-	w := rect.Dx()
-	h := rect.Dy()
-	return []prop.Media{
-		{
-			DeviceID: deviceID(s.num),
-			Video: prop.Video{
-				Width:       w,
-				Height:      h,
-				FrameFormat: frame.FormatRGBA,
-			},
-		},
-	}
-}