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
if (has_response_started) {
    return SiteInstanceForNavigationType::FORCE_CURRENT;
  }
  return SiteInstanceForNavigationType::FORCE_CANDIDATE_OR_NEW;
}
void AtomBrowserClient::RegisterPendingSiteInstance(
    content::RenderFrameHost* rfh,
    content::SiteInstance* pending_site_instance) {
  
  ConsiderSiteInstanceForAffinity(rfh, pending_site_instance);
  
  auto* web_contents = content::WebContents::FromRenderFrameHost(rfh);
  auto* pending_process = pending_site_instance->GetProcess();
  pending_processes_[pending_process->GetID()] = web_contents;
  if (rfh->GetParent())
    renderer_is_subframe_.insert(pending_process->GetID());
  else
    renderer_is_subframe_.erase(pending_process->GetID());
}
void AtomBrowserClient::AppendExtraCommandLineSwitches(