Examine source code of Middle Click Scroll

{
  "manifest_version": 2,
  "name": "Middle Click Scroll",
  "description": "Replaces the middle mouse button click with a scrolling function.",
  "version": "6.9",
  "browser_action": {
    "default_icon": "scrolling.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ],
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{53082585-3a43-4ec7-989c-57d0f23b22da}"
    }
  }
}