Examine source code of Search Engine Switchers

{
  "manifest_version": 2,
  "name": "Search Engine Switcher",
  "version": "1.0",
  "description": "Quickly switch your search queries between different search engines.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png",
    "default_title": "Search Engine Switcher"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{14e20217-02ad-4524-9c34-a3d0fb710d3d}"
    }
  }
}