SwizzleSafariStatusBar.swift

class Dummy: NSObject {
    
    @objc func barStyle() -> UIStatusBarStyle {
        return .LightContent
    }
    
    func swizzle() {
        
        guard let safariClass = NSClassFromString("SFSafariViewController") else {
            print("can't swizzle, iOS 8")
            return
        }
        let replacementMethod: Method = class_getInstanceMethod(object_getClass(self), "barStyle")
        
        let swizzledMethod = class_getInstanceMethod(safariClass, "preferredStatusBarStyle")
        
        method_exchangeImplementations(replacementMethod, swizzledMethod)
    }
}

// Elsewhere (i.e. applicationDidFinishLaunching) I call Dummy().swizzle() to run this code.

This works around not being able to change SFSafariViewController's status bar color on an app that is deploying to iOS 9.