Examine source code of oldRedirect

{
  "manifest_version": 2,
  "name": "oldReddirect",
  "version": "1.0",
  "description": "Redirects reddit.com to old.reddit.com",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*.reddit.com/"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3fad827d-18cc-4093-b276-4a0a62b4caf2}"
    }
  }
}