Examine source code of History Cleaner

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.7.0",
  "description": "__MSG_extensionDescription__",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a138007c-5ff6-4d10-83d9-0afaf0efbe5e}"
    }
  },
  "icons": {
    "96": "icons/icon.svg"
  },
  "background": {
    "scripts": [
      "background.bundle.js"
    ]
  },
  "permissions": [
    "history",
    "storage",
    "idle",
    "alarms"
  ],
  "optional_permissions": [
    "notifications",
    "downloads"
  ],
  "options_ui": {
    "page": "popup.html",
    "browser_style": true
  },
  "browser_action": {
    "default_icon": "icons/icon.svg",
    "default_popup": "popup.html"
  },
  "default_locale": "en_US"
}