Examine source code of BingDictionary

{
  "manifest_version": 2,
  "name": "BingDictionary",
  "version": "1.2resigned1",
  "description": "Right click and easy search Bing dictionary",
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "bing-dict.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d827fc10-b8f4-4d32-9b41-4c2e5ff614d4}"
    }
  }
}