Examine source code of Origin Lock

{
  "author": "igorlogius",
  "homepage_url": "https://github.com/igorlogius/origin-lock",
  "description": "lock a tab to a origin (aka. protocol + domain + port) to prevent accidentally external navigations",
  "browser_action": {
    "default_area": "navbar"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "87": "icon.png"
  },
  "manifest_version": 2,
  "name": "Origin Lock",
  "permissions": [
    "<all_urls>",
    "webRequest",
    "tabs",
    "webRequestBlocking"
  ],
  "version": "1.0.7",
  "browser_specific_settings": {
    "gecko": {
      "id": "{8fa9540a-3885-45c4-ae34-4fa0a0925257}"
    }
  }
}