Examine source code of History Deleter

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Gives a popup to list and delete history on a domain.",
  "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/history-deleter",
  "page_action": {
    "default_title": "History deleter",
    "default_popup": "history.html",
    "default_icon": "icons/history.svg"
  },
  "icons": {
    "48": "icons/history.svg",
    "96": "icons/history.svg"
  },
  "permissions": [
    "activeTab",
    "history",
    "tabs"
  ],
  "manifest_version": 2,
  "name": "History Deleter",
  "version": "3.0"
}