Examine source code of Automatic Scroll

{
  "manifest_version": 2,
  "name": "Automatic Scroll",
  "version": "1.1",
  "description": "Automatically scroll down the page with selected speed.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{0e1c8acd-8336-47bc-b19c-a03dc540c314}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_title": "Automatic Scroll",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/48.png",
      "64": "icons/64.png",
      "128": "icons/128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}