Examine source code of GCMNetCache

{
  "manifest_version": 2,
  "name": "GCMNetCache",
  "short_name": "GCMNetCache",
  "description": "チュウニズム/maimai/オンゲキのNETページの転送量を削減する試み。",
  "version": "0.1.0",
  "version_name": "0.1.0",
  "developer": {
    "name": "CYakigasi"
  },
  "homepage_url": "https://github.com/castella-cake/gcmnetcache-extension",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*.maimaidx.jp/*",
    "*://new.chunithm-net.com/chuni-mobile/*",
    "*://ongeki-net.com/ongeki-mobile/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "gcmnetcache@cyakigasi.net"
    }
  }
}