Examine source code of Element Remover

{
  "manifest_version": 2,
  "name": "Element Remover",
  "description": "Allows removing elements from webpages",
  "version": "1.0.0",
  "icons": {
    "48": "remove_icon-48.acd4abf0.png",
    "96": "remove_icon-96.9d1d83aa.png"
  },
  "permissions": [
    "<all_urls>",
    "menus",
    "activeTab"
  ],
  "background": {
    "page": "background.3f18a83c.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.c7beb992.js"
      ],
      "css": []
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{351947d6-1b77-43a6-beb2-6dd4ea13d53e}"
    }
  }
}