* Electron Version 6.0.0-beta.12
* Operating System Windows 10 64 bit

Expected Behavior
webContents.print() should send print a job to the specified printer

Actual behavior
Nothing happens. Callback gets called much latter, for example on program exit.

To Reproduce
let print_options = { 
    silent: true,
    printBackground: true,
    deviceName: barcode_device_name 
}
print_window.webContents.print(print_options, (data) => {
    console.log(`print result: ${data}`)
})

Related to #17260
shell/browser/api/atom_api_web_contents.cc
if (IsOffScreen() && wc == web_contents()) {
    auto* relay = NativeWindowRelay::FromWebContents(web_contents());
    if (relay) {
      auto* owner_window = relay->GetNativeWindow();
      return owner_window ? owner_window->GetSize() : gfx::Size();
    }
  }
  return gfx::Size();
}
void WebContents::SetZoomLevel(double level) {
  zoom_controller_->SetZoomLevel(level);
}
double WebContents::GetZoomLevel() const {
  return zoom_controller_->GetZoomLevel();
}
void WebContents::SetZoomFactor(double factor) {
  auto level = content::ZoomFactorToZoomLevel(factor);
  SetZoomLevel(level);
}
double WebContents::GetZoomFactor() const {
  auto level = GetZoomLevel();
  return content::ZoomLevelToZoomFactor(level);
}
void WebContents::SetTemporaryZoomLevel(double level) {
  zoom_controller_->SetTemporaryZoomLevel(level);
}
void WebContents::DoGetZoomLevel(DoGetZoomLevelCallback callback) {