Examine source code of Javascript Injector

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "name": "Javascript Injector",
  "version": "0.0.3",
  "manifest_version": 2,
  "icons": {
    "128": "icon.png"
  },
  "description": "Inject any javascript code from Url in the content page (only for developers).",
  "permissions": [
    "<all_urls>",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}