Examine source code of Long Screenshot

{
  "manifest_version": 2,
  "name": "Long Screenshot",
  "version": "0.3resigned1",
  "description": "Screenshots all page content and saves the result as a png. Also has an option to auto scroll to preload elements of the page before taking a screenshot.",
  "permissions": [
    "<all_urls>",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "32": "icon.png"
    },
    "default_title": "Long Screenshot",
    "default_popup": "popup/main.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9e90c498-6025-470e-8463-0ef02221a60c}"
    }
  }
}