Examine source code of Close Active Window

{
  "author": "igorlogius",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {},
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+F10"
      }
    }
  },
  "icons": {
    "128": "icon.png"
  },
  "manifest_version": 2,
  "name": "Close Active Window",
  "permissions": [
    "menus"
  ],
  "version": "1.3.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{46f03819-30cb-4d0d-96a7-ee79a0b6af0f}"
    }
  }
}