Examine source code of Request Dropper

{
  "manifest_version": 2,
  "name": "URL Blocker",
  "version": "1.0",
  "description": "Blocks specified URLs or URL patterns.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "URL Blocker"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f7fd9850-9844-49f1-97a9-9c566aa72189}"
    }
  }
}