Examine source code of Network Speed Tester

{
  "manifest_version": 2,
  "name": "Network Speed Tester",
  "version": "1.0",
  "description": "Kiểm tra tốc độ mạng bằng Speedtest.net",
  "icons": {
    "48": "icons/icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_title": "Network Speed Tester"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b2799d5a-d24a-4375-b389-70d3d1f9f394}"
    }
  }
}