Examine source code of Video Watch Tracker

{
  "version": "0.0.5",
  "background": {
    "scripts": [
      "js/service-worker.js"
    ]
  },
  "content_scripts": [
    {
      "js": [
        "js/contents.js"
      ],
      "matches": [
        "https://*.nicovideo.jp/*",
        "https://nicovideo.jp/*",
        "https://youtube.com/*",
        "https://*.youtube.com/*"
      ]
    }
  ],
  "icons": {
    "64": "img/64.png"
  },
  "permissions": [
    "storage"
  ],
  "default_locale": "en",
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{92f2023e-a89a-4139-a88b-eceaca863e7b}"
    }
  }
}