These events are emitted for every navigation request which isn't really efficient. Also upstream has removed the observers that provide these details as part of network servification https://chromium-review.googlesource.com/c/chromium/src/+/805008 and https://chromium-review.googlesource.com/c/chromium/src/+/786320. We are removing it as a part of chromium 66 upgrade.

Proposed alternative: Users can use the [webRequest](https://github.com/electron/electron/blob/master/docs/api/web-request.md) module which provides similar navigation details on a subscription basis.
atom/browser/api/atom_api_web_contents.cc
if (managed_web_contents()) {
    managed_web_contents()->GetView()->SetDelegate(nullptr);
    
    
    if (type_ == WEB_VIEW)
      guest_delegate_->Destroy();
    RenderViewDeleted(web_contents()->GetRenderViewHost());
    if (type_ == WEB_VIEW) {
      DestroyWebContents(false );
    } else {
      if (type_ == BROWSER_WINDOW && owner_window()) {
        for (ExtendedWebContentsObserver& observer : observers_)
          observer.OnCloseContents();
      } else {
        DestroyWebContents(true );
      }
      
      
      
      WebContentsDestroyed();
    }
  }
}
void WebContents::DestroyWebContents(bool async) {