Examine source code of Indian CSS Inject

{
  "name": "Indian CSS Inject",
  "version": "1.1.0",
  "description": "Allow multiple stylesheets ready to inject and change",
  "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": [
        "IndianCSSInject.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
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5782b54b-2f2e-4ac8-b78f-55060d6d995f}"
    }
  }
}