### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Problem Description

We need to load a custom error page when the certificate is invalid but without "isMainFrame" property we don't know when to load the custom error page using webContents.loadURL()

### Proposed Solution

webContents.on("certificate-error", ((event, url, error, certificate, callback, isMainFrame)

### Alternatives Considered

Not sure

### Additional Information

Not sure
shell/browser/api/electron_api_app.cc
return ElectronBrowserClient::Get()->GetUserAgent();
}
#if defined(OS_MAC)
bool App::MoveToApplicationsFolder(gin_helper::ErrorThrower thrower,
                                   gin::Arguments* args) {
  return ElectronBundleMover::Move(thrower, args);
}
bool App::IsInApplicationsFolder() {
  return ElectronBundleMover::IsCurrentAppInApplicationsFolder();
}
int DockBounce(gin::Arguments* args) {
  int request_id = -1;
  std::string type = "informational";
  args->GetNext(&type);
  if (type == "critical")
    request_id = Browser::Get()->DockBounce(Browser::BounceType::kCritical);
  else if (type == "informational")
    request_id =
        Browser::Get()->DockBounce(Browser::BounceType::kInformational);
  return request_id;
}
void DockSetMenu(electron::api::Menu* menu) {