Examine source code of PageSpeed Insights

{
  "manifest_version": 2,
  "name": "PageSpeed Insights",
  "version": "1.4",
  "description": "PageSpeed Insights is a Google tool that measures the loading speed of a web page.",
  "icons": {
    "16": "icons/16.png",
    "24": "icons/24.png",
    "32": "icons/32.png",
    "64": "icons/64.png",
    "128": "icons/128.png",
    "256": "icons/256.png",
    "512": "icons/512.png"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "permissions": [
    "contextMenus",
    "activeTab",
    "tabs"
  ]
}