It's going to be removed from Chromium, see https://crbug.com/812523.

/cc @electron/code-owners 
shell/browser/api/electron_api_app.cc
content::RenderFrameHost* opener,
    const GURL& opener_url,
    const GURL& opener_top_level_frame_url,
    const url::Origin& source_origin,
    content::mojom::WindowContainerType container_type,
    const GURL& target_url,
    const content::Referrer& referrer,
    const std::string& frame_name,
    WindowOpenDisposition disposition,
    const blink::mojom::WindowFeatures& features,
    const std::string& raw_features,
    const scoped_refptr<network::ResourceRequestBody>& body,
    bool user_gesture,
    bool opener_suppressed,
    bool* no_javascript_access) {
  v8::Locker locker(isolate());
  v8::HandleScope handle_scope(isolate());
  content::WebContents* web_contents =
      content::WebContents::FromRenderFrameHost(opener);
  if (web_contents) {
    auto api_web_contents = WebContents::From(isolate(), web_contents);
    
    if (!api_web_contents.IsEmpty()) {
      api_web_contents->OnCreateWindow(target_url, referrer, frame_name,
                                       disposition, raw_features, body);
    }
  }
  return false;
}
void App::AllowCertificateError(