syscall/js.TypedArrayOf is going away in Go 1.13. Avoid it for invalidateFramebuffer by using a buffer managed by JS. Signed-off-by: Elias Naur <mail@eliasnaur.com>
It is still slow. And crashy: https://github.com/golang/go/issues/31980. Signed-off-by: Elias Naur <mail@eliasnaur.com>