Examine source code of Youtube Unembed

{
  "manifest_version": 2,
  "name": "Youtube Unembed",
  "version": "0.0.1",
  "applications": {
    "gecko": {
      "id": "youtube-unembed@erikgibbons.com"
    }
  },
  "description": "Prevents embedded recommendations from obscuring video content.",
  "icons": {
    "48": "icons/yu-48.png",
    "96": "icons/yu-96.png",
    "128": "icons/yu-96-128.png"
  },
  "browser_action": {
    "default_icon": "icons/yu-38.png",
    "default_popup": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "yu.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage"
  ]
}