Examine source code of Delete History

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "2.3",
  "author": "dsrini.open",
  "homepage_url": "https://github.com/dsrini-open/history-delete",
  "developer": {
    "name": "dsrini.open",
    "url": "https://github.com/dsrini-open"
  },
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "history-delete@dsrini-open.github.com",
      "strict_min_version": "56.0"
    }
  },
  "permissions": [
    "alarms",
    "notifications",
    "storage",
    "history",
    "tabs",
    "<all_urls>"
  ],
  "content_security_policy": "default-src 'self'; style-src 'self' 'unsafe-inline';",
  "browser_action": {
    "default_icon": {
      "32": "src/assets/icon-32.png",
      "48": "src/assets/icon-48.png",
      "64": "src/assets/icon-64.png"
    },
    "browser_style": false
  },
  "options_ui": {
    "page": "src/settings/settings.html",
    "browser_style": false,
    "open_in_tab": true
  },
  "background": {
    "page": "src/background/background.html"
  }
}