Examine source code of Crossref Search

{
  "name": "Crossref Search",
  "version": "2.3resigned1",
  "description": "__MSG_manifest_description__",
  "minimum_chrome_version": "18",
  "manifest_version": 2,
  "background": {
    "page": "background.html"
  },
  "icons": {
    "16": "images/icon-16.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "default_locale": "en",
  "permissions": [
    "contextMenus"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{9f824a2c-bf12-45fd-8c62-d759766ad716}"
    }
  }
}