Examine source code of Tab Play

{
  "manifest_version": 2,
  "name": "Tab Play",
  "version": "1.1",
  "description": "Watch Youtube videos in separate browser windows",
  "permissions": [
    "activeTab",
    "tabs",
    "menus",
    "notifications",
    "contextMenus",
    "storage"
  ],
  "browser_action": {
    "default_title": "TabPlay",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/embed/*"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{745b4119-fedd-4533-940c-60879162aa7c}"
    }
  }
}