Examine source code of Disable Autoplay

{
  "manifest_version": 2,
  "name": "Disable Autoplay",
  "version": "1.0",
  "description": "Disables autoplay of media on web pages.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{769a8be0-90e1-4d4a-9843-c648ea1e7ff9}"
    }
  }
}