Examine source code of Netflix Shuffle

{
  "applications": {
    "gecko": {
      "id": "netflixshuffle@mozilla.org",
      "strict_min_version": "45.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "data/icon-64.png",
    "default_title": "Netflix Shuffle"
  },
  "description": "Netflix Shuffle adds a button that detects which Netflix show page the user is on, and plays a random episode from that show.",
  "icons": {
    "64": "data/icon-64.png",
    "128": "data/icon-128.png",
    "256": "data/icon-256.png",
    "512": "data/icon-512.png"
  },
  "manifest_version": 2,
  "name": "Netflix Shuffle",
  "permissions": [
    "activeTab",
    "notifications",
    "tabs"
  ],
  "version": "1.2resigned1"
}