- Electron version: 1.1.0
- Operating system: Windows
- Use case: cleanup and reporting tasks executed on quit (headless), which may take time and should not prevent from opening a new instance.
- Proposed solutions:
  - new _app.releaseSingleInstance()_ API which free the singleInstance lock
  - replace _app.releaseSingleInstance()_ API by an event listener (which may be listened/unlistened)
  - [app.makeSingleInstance](https://github.com/electron/electron/blob/master/docs/api/app.md#appmakesingleinstancecallback) returns the result of the callback function. So we can choose to quit or not in a more accurate way.
  - Provide a communication channel between the new instance and the main one (in callback arguments)

atom/browser/api/atom_api_app.cc
v8::Isolate* isolate,
    std::shared_ptr<content::ClientCertificateDelegate> delegate,
    mate::Arguments* args) {
  mate::Dictionary cert_data;
  if (!args->GetNext(&cert_data)) {
    args->ThrowError();
    return;
  }
  v8::Local<v8::Object> data;
  if (!cert_data.Get("data", &data))
    return;
  auto certs = net::X509Certificate::CreateCertificateListFromBytes(
      node::Buffer::Data(data), node::Buffer::Length(data),
      net::X509Certificate::FORMAT_AUTO);
  if (certs.size() > 0)
    delegate->ContinueWithCertificate(certs[0].get());
}
void PassLoginInformation(scoped_refptr<LoginHandler> login_handler,
                          mate::Arguments* args) {
  base::string16 username, password;
  if (args->GetNext(&username) && args->GetNext(&password))
    login_handler->Login(username, password);
  else
    login_handler->CancelAuth();
}
#if defined(USE_NSS_CERTS)
int ImportIntoCertStore(