Examine source code of Switch for YouTube

{
  "manifest_version": 2,
  "name": "Switch for YouTube",
  "version": "0.4resigned1",
  "icons": {
    "48": "images/icon-mini.png",
    "96": "images/icon-small.png",
    "128": "images/icon-medium.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "cookies",
    "*://*.youtube.com/"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "http://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "images/icon-medium.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1d080ce7-4fa3-4bcb-8d4c-7bbb9c2e91e6}"
    }
  }
}