Examine source code of Stop next video

{
  "name": "Stop next video",
  "version": "0.0.4",
  "description": "Prevent auto-playing next video on Facebook",
  "icons": {
    "16": "icons-on/icon.16.png",
    "48": "icons-on/icon.48.png",
    "128": "icons-on/icon.128.png"
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "https://*.facebook.com/*"
      ],
      "js": [
        "cs.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "bg.js"
    ],
    "persistent": false
  }
}