No need to swap skia surface R & B

[rustytsuki]

skia surface type can be set by skia_safe::core::image_info::ColorType:
like following code.
let image_info = ImageInfo::new((px_w, px_h), ColorType::RGBA8888, AlphaType::Premul, None);
let surface = Surface::new_raster(&image_info, None, None).unwrap();