Examine source code of YouTube Speed Control

{
  "name": "YouTube Speed Control",
  "short_name": "YT Speed",
  "description": "Control the speed of YouTube videos!",
  "version": "2.1.7",
  "manifest_version": 2,
  "author": "avi12",
  "developer": {
    "name": "avi12",
    "url": "https://avi12.com/youtube-speed-control"
  },
  "icons": {
    "16": "images/icon-16.png",
    "19": "images/icon-19.png",
    "24": "images/icon-24.png",
    "32": "images/icon-32.png",
    "38": "images/icon-38.png",
    "48": "images/icon-48.png",
    "64": "images/icon-64.png",
    "96": "images/icon-96.png",
    "128": "images/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.youtube.com/*",
        "https://*.youtube-nocookie.com/*"
      ],
      "js": [
        "build/scripts/ytsc-content-script-initialize.js"
      ],
      "css": [
        "build/styles-injected/main.css"
      ],
      "all_frames": true
    }
  ],
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-speed-control@avi12.com"
    }
  },
  "browser_action": {
    "default_title": "YouTube Speed Control",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/icon-16.png",
      "19": "images/icon-19.png",
      "24": "images/icon-24.png",
      "32": "images/icon-32.png",
      "38": "images/icon-38.png",
      "48": "images/icon-48.png",
      "64": "images/icon-64.png",
      "96": "images/icon-96.png",
      "128": "images/icon-128.png"
    }
  }
}