Examine source code of YT Album Player

{
  "manifest_version": 2,
  "name": "YT Album Player",
  "version": "1.1",
  "description": "Display a notification when a new song in a YouTube full album video starts playing. No more trawling through track lists in video description and comments!",
  "icons": {
    "128": "icons/play128.png"
  },
  "background": {
    "scripts": [
      "background-script.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/watch*"
      ],
      "js": [
        "lodash.min.js",
        "extract-information.js",
        "tracklist-candidates.js",
        "content-script.js"
      ]
    }
  ],
  "permissions": [
    "notifications",
    "storage"
  ],
  "web_accessible_resources": [
    "icons/*.png"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/play48.png"
    }
  }
}