Examine source code of Speedtest by Ookla

{
  "background": {
    "page": "/background.html"
  },
  "browser_action": {
    "default_icon": {
      "19": "images/gauge-19.png",
      "38": "images/gauge-38.png"
    },
    "default_popup": "index.html",
    "default_title": "Speedtest"
  },
  "content_scripts": [
    {
      "js": [
        "webspeed.js"
      ],
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "run_at": "document_end"
    }
  ],
  "content_security_policy": "script-src 'self' https://www.speedtest.net https://www.googletagmanager.com/gtm.js https://www.google-analytics.com/analytics.js; object-src 'self'",
  "default_locale": "en",
  "description": "__MSG_extDescription__",
  "icons": {
    "16": "images/gauge-16.png",
    "48": "images/gauge-48.png",
    "128": "images/gauge-128.png"
  },
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoCt7UPjDs3ueWsmkGOsIFW5losKjnM4ZBnZEuiDQZuJa7nHwJFBwdJosWB/Acp1ZQIG/pHNvzHp/k1N+BVsl9hArB/y0NYKPcOfts75CdniwyAW1mLRFsNI4iO+tZgNimF2+6FhU6rp3jp/ky+pwFUwd+BliIsTiJi3CB+CayQx5+aUkxmCbYuc6IIL9zMjas73YqH4lXB8gJkYtFSVpqSEpNac0MYSdZv81hpHeFSjMcBMQMQJHrelVX9AAJB80rS5tVkAlsJCZS20tg4vOV+oNTRvPp634AqZgB3bV2zzfdIzpUGiwbNb0EVrnJv9dXLQ5+glxhK9V/DA3zcD3UwIDAQAB",
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "options_page": "index.html?options=true",
  "permissions": [
    "webRequest",
    "background",
    "storage",
    "tabs"
  ],
  "short_name": "Speedtest",
  "update_url": "https://clients2.google.com/service/update2/crx",
  "version": "1.0.9.10",
  "browser_specific_settings": {
    "gecko": {
      "id": "{8709b466-0b85-4687-8964-e4d0f693d7ed}"
    }
  }
}