Examine source code of YouTube Pause Button

{
  "manifest_version": 2,
  "name": "Simple YouTube Toggler",
  "version": "1.2",
  "description": "Toggle YouTube videos between play and pause, even in background tabs, and update the icon on manual changes.",
  "permissions": [
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/icon.png",
      "48": "icons/icon.png",
      "128": "icons/icon.png"
    }
  },
  "icons": {
    "128": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a45e26e6-d509-452f-84c3-c96c7b6c42e3}"
    }
  }
}