Examine source code of DNS Leak Detector

{
  "manifest_version": 2,
  "name": "DNS Leak Detector",
  "version": "1.0.1",
  "description": "__MSG_ext_description__",
  "default_locale": "en",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "__MSG_ext_name__",
    "default_popup": "popup.html"
  },
  "permissions": [
    "dns",
    "webRequest",
    "webRequestBlocking",
    "tabs",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{3f8d2daf-85af-4e42-aef4-6ca36a9a2917}",
      "strict_min_version": "120.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  }
}