void WebContents::BeforeUnloadFired(bool proceed,
                                    const base::TimeTicks& proceed_time) {
  // Do nothing, we override this method just to avoid compilation error since
  // there are two virtual functions named BeforeUnloadFired.
}
void WebContents::BeforeUnloadFired(bool proceed,
                                    const base::TimeTicks& proceed_time) {
   
   
}