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
#include "content/public/browser/browser_ppapi_host.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/client_certificate_delegate.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/site_instance.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/content_paths.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/service_names.mojom.h"
#include "content/public/common/url_constants.h"
#include "content/public/common/web_preferences.h"
#include "electron/buildflags/buildflags.h"
#include "electron/grit/electron_resources.h"
#include "net/base/escape.h"
#include "net/ssl/ssl_cert_request_info.h"
#include "ppapi/host/ppapi_host.h"
#include "printing/buildflags/buildflags.h"
#include "services/device/public/cpp/geolocation/location_provider.h"
#include "services/network/public/cpp/features.h"
#include "services/network/public/cpp/resource_request_body.h"
#include "shell/app/manifests.h"
#include "shell/browser/api/atom_api_app.h"
#include "shell/browser/api/atom_api_protocol.h"
#include "shell/browser/api/atom_api_protocol_ns.h"
#include "shell/browser/api/atom_api_web_contents.h"
#include "shell/browser/atom_browser_context.h"
#include "shell/browser/atom_browser_main_parts.h"
#include "shell/browser/atom_navigation_throttle.h"