Examine source code of ScrollToTop

{
  "manifest_version": 2,
  "name": "ScrollToTop",
  "version": "2.1resigned1",
  "description": "Scrolls instantly to top.",
  "icons": {
    "48": "assets/up-arrow48.png",
    "128": "assets/up-arrow128.png",
    "512": "assets/up-arrow512.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_title": "Scroll up",
    "default_icon": {
      "16": "assets/up-arrow16.png",
      "32": "assets/up-arrow32.png",
      "48": "assets/up-arrow48.png",
      "128": "assets/up-arrow128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b4fbcfd0-e862-44e6-8995-82e0a300fdd5}"
    }
  }
}