Safari Technology Preview now supports dark mode via `@media (prefers-color-scheme: dark)` in CSS media queries. 

Same should be supported in Electron apps to enable automatic light/dark mode switching.

shell/browser/atom_browser_client.cc
content::BrowserContext* browser_context,
    content::RenderFrameHost* frame_host,
    int render_process_id,
    bool is_navigation,
    bool is_download,
    const url::Origin& request_initiator,
    network::mojom::URLLoaderFactoryRequest* factory_request,
    network::mojom::TrustedURLLoaderHeaderClientPtrInfo* header_client,
    bool* bypass_redirect_checks) {
  content::WebContents* web_contents =
      content::WebContents::FromRenderFrameHost(frame_host);
  api::ProtocolNS* protocol = api::ProtocolNS::FromWrappedClass(
      v8::Isolate::GetCurrent(), web_contents->GetBrowserContext());
  if (!protocol)
    return false;
  auto proxied_request = std::move(*factory_request);
  network::mojom::URLLoaderFactoryPtrInfo target_factory_info;
  *factory_request = mojo::MakeRequest(&target_factory_info);
  new ProxyingURLLoaderFactory(protocol->intercept_handlers(),
                               std::move(proxied_request),
                               std::move(target_factory_info));
  return true;
}
#if defined(OS_WIN)
bool AtomBrowserClient::PreSpawnRenderer(sandbox::TargetPolicy* policy) {