Examine source code of Allow SSO iFrames

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Drops and changes HTTP response headers to allow sso login pages to be iframed.",
  "manifest_version": 2,
  "name": "Allow SSO iFrames",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "homepage_url": "https://github.com/chaptergy/webextension-allow-sso-iframes",
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "version": "1.1"
}