Examine source code of Switch Direction

{
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Switch Direction in edits, useful for mixed RTL and LTR texts.",
  "icons": {
    "16": "icon_16.png",
    "48": "icon_48.png",
    "128": "icon_128.png"
  },
  "name": "Switch Direction",
  "options_page": "options.html",
  "permissions": [
    "contextMenus",
    "tabs",
    "<all_urls>"
  ],
  "default_locale": "en",
  "version": "0.7resigned1",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a7c15b17-7654-4284-b8cb-612ae2d1c9a1}"
    }
  }
}