Examine source code of Super CSS Inject

{
  "name" : "Super CSS Inject",
  "version" : "1.2.0",
  "description" : "Keep multiple stylesheets ready to inject and change on the fly!",
  "manifest_version" : 2 ,
  "permissions" : [
    "activeTab" ,
    "storage" 
  ],
  "icons" : {
    "48" : "icons/48x48.png",
    "64" : "icons/64x64.png",
    "128" : "icons/128x128.png"
  },
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "content_scripts" : [
    {
      "js" : [
        "SuperCSSInject.js" 
      ],
      "matches" : [
        "http://*/*" ,
        "https://*/*" 
      ],
      "run_at" : "document_end" 
    }
  ],
  "browser_action" : {
    "default_title" : "Enable Super CSS Inject",
    "default_icon" : "icons/48x48.png",
    "default_popup" : "popup.html"
  },
  "options_ui" : {
    "page": "options.html" ,
    "open_in_tab": true
  }
}