Examine source code of Rotate Page Controls

{
  "manifest_version": 2,
  "name": "Rotate Page Controls",
  "version": "1.1",
  "description": "Rotate the entire webpage clockwise or anti-clockwise, or reset.",
  "browser_action": {
    "default_title": "Show Rotate Controls"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d4643c89-3883-4294-a728-50a14773b2e6}"
    }
  }
}