Examine source code of Giving Assistant Button

{
  "name": "Giving Assistant Button",
  "version": "7.3.18",
  "author": "Giving Assistant",
  "description": "Giving Assistant Button",
  "background": {
    "page": "bg.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "js/vendor.chunk.js",
        "js/contentScript.bundle.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "icons": {
    "16": "img/givva-16.png",
    "32": "img/givva-32.png",
    "48": "img/givva-48.png",
    "64": "img/givva-64.png",
    "128": "img/givva-128.png"
  },
  "browser_action": {
    "default_title": "Giving Assistant Button",
    "default_icon": {
      "16": "img/givva-bw-16.png",
      "32": "img/givva-bw-32.png",
      "48": "img/givva-bw-48.png",
      "64": "img/givva-bw-64.png",
      "128": "img/givva-bw-128.png"
    }
  },
  "web_accessible_resources": [
    "iframes/*"
  ],
  "permissions": [
    "cookies",
    "webRequest",
    "webRequestBlocking",
    "http://*/*",
    "https://*/*",
    "tabs",
    "notifications",
    "storage"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self';",
  "manifest_version": 2
}