feat: remove needless mojave dark mode APIs and add instructions on how to use the macOS replacement (#14895)

lib/browser/api/system-preferences.js

@@ -1,6 +1,5 @@
 'use strict'
 
-const { app } = require('electron')
 const { EventEmitter } = require('events')
 const { systemPreferences, SystemPreferences } = process.atomBinding('system_preferences')
 
@@ -8,40 +7,4 @@ const { systemPreferences, SystemPreferences } = process.atomBinding('system_pre
 Object.setPrototypeOf(SystemPreferences.prototype, EventEmitter.prototype)
 EventEmitter.call(systemPreferences)
 
-if (process.platform === 'darwin') {
-  let appearanceTrackingSubscriptionID = null
-
-  systemPreferences.startAppLevelAppearanceTrackingOS = () => {
-    if (appearanceTrackingSubscriptionID !== null) return
-
-    const updateAppearanceBasedOnOS = () => {
-      const newAppearance = systemPreferences.isDarkMode()
-        ? 'dark'
-        : 'light'
-
-      if (systemPreferences.getAppLevelAppearance() !== newAppearance) {
-        systemPreferences.setAppLevelAppearance(newAppearance)
-        // TODO(MarshallOfSound): Once we remove this logic and build against 10.14
-        // SDK we should re-implement this event as a monitor of `effectiveAppearance`
-        systemPreferences.emit('appearance-changed', newAppearance)
-      }
-    }
-
-    appearanceTrackingSubscriptionID = systemPreferences.subscribeNotification(
-      'AppleInterfaceThemeChangedNotification',
-      updateAppearanceBasedOnOS
-    )
-
-    updateAppearanceBasedOnOS()
-  }
-
-  systemPreferences.stopAppLevelAppearanceTrackingOS = () => {
-    if (appearanceTrackingSubscriptionID === null) return
-
-    systemPreferences.unsubscribeNotification(appearanceTrackingSubscriptionID)
-  }
-
-  app.on('quit', systemPreferences.stopAppLevelAppearanceTrackingOS)
-}
-
 module.exports = systemPreferences