Examine source code of Audio Visualizer

{
  "manifest_version": 2,
  "name": "Audio Visualizer",
  "version": "1.0",
  "description": "Visualizer tạo hiệu ứng sóng âm nhạc.",
  "permissions": [
    "activeTab",
    "microphone"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{16f90314-4824-4e2f-8377-b4c621d4f283}"
    }
  }
}