Examine source code of nicoExpansion

{
  "manifest_version": 2,
  "name": "nicoExpansion",
  "version": "3.10.22",
  "description": "ニコニコに関する便利機能を追加します",
  "icons": {
    "32": "icons/nicoExp32.png",
    "128": "icons/nicoExp128.png",
    "256": "icons/nicoExp256.png",
    "512": "icons/nicoExp512.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.nicovideo.jp/*"
      ],
      "js": [
        "script/ncid.js",
        "script/el.js",
        "script/main.js"
      ],
      "css": [
        "style/common.css",
        "style/nicodark_ex.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "*://www.nicovideo.jp/watch/*"
      ],
      "css": [
        "style/video.css"
      ]
    },
    {
      "matches": [
        "*://www.nicovideo.jp/my/mylist/*"
      ],
      "css": [
        "style/exlist.css"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "script/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "tabs",
    "contextMenus",
    "clipboardWrite",
    "*://ext.nicovideo.jp/api/getthumbinfo/*",
    "*://seiga.nicovideo.jp/ajax/*",
    "*://*.nicovideo.jp/*"
  ],
  "web_accessible_resources": [
    "icons/nicoExp32.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8b8bf33-a4ef-4fd0-9ab1-3a6a6cbcd2eb}"
    }
  }
}