Function msg_surface_resize 

pub fn msg_surface_resize(
    surface_id: u16,
    width: u16,
    height: u16,
    scale_120: u16,
) -> Vec<u8> 

scale_120 is the device-pixel-ratio in 1/120th units, matching Wayland’s fractional_scale_v1 convention: 120 = 1×, 180 = 1.5×, 240 = 2×. A value of 0 means “unspecified” (server defaults to 1×).