Function decide 

pub fn decide(
    url: &str,
    opener_url: &str,
    user_gesture: bool,
    opener_owned: bool,
    open_popups: usize,
) -> Result<(), Refusal>

Is this request honored?

• only one the user (or the agent driving the pane, whose clicks are real input events) caused: a script with no gesture opens nothing new;
• an http(s) page;
• fewer than MAX_POPUPS_PER_PANE of its kind already open;
• and either an agent owns the opener, so the window is part of what that agent is doing and must stay where it can drive it, or the target is on the opener’s own site.