Examine source code of Crunchyroll Mix Dub Sub

{
  "manifest_version": 2,
  "name": "CrunchyrollMixDubSub",
  "version": "2.2",
  "description": "mix dub and sub in crunchyroll",
  "icons": {
    "48": "icon48.png",
    "96": "icon96.png"
  },
  "permissions": [
    "https://www.crunchyroll.com/*",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.crunchyroll.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{cf99ccc9-6403-43ab-babf-9532b174b433}"
    }
  }
}