Examine source code of Replace Steam CDN

{
  "manifest_version": 2,
  "name": "Replace Steam CDN",
  "version": "1.5.0",
  "description": "Replace Steam CDN with Addones CDN.",
  "icons": {
    "128": "icons/128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://store.steampowered.com/*",
    "*://steamcommunity.com/*",
    "*://steamcdn-a.akamaihd.net/*",
    "*://steamstore-a.akamaihd.net/*",
    "*://steamcommunity-a.akamaihd.net/*",
    "*://steamuserimages-a.akamaihd.net/*",
    "*://cdn.steamstatic.com.8686c.com/*",
    "*://steambroadcast.akamaized.net/*"
  ],
  "author": "https://github.com/teakowa",
  "homepage_url": "https://github.com/Teakowa/Replace-Steam-CDN"
}