Examine source code of Load Time Plus

{
  "manifest_version": 2,
  "name": "Load Time",
  "version": "1.0.20",
  "description": "Shows the load time of a web page in the toolbar and provides a breakdown using Navigation Timings.",
  "icons": {
    "16": "img/index16.png",
    "32": "img/index32.png",
    "48": "img/index48.png",
    "128": "img/index128.png"
  },
  "browser_action": {
    "default_icon": "img/index128.png",
    "default_title": "Load Time"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self';",
  "web_accessible_resources": [
    "img/index16.png",
    "img/index32.png",
    "img/index48.png",
    "img/index128.png",
    "js/background.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5eaccb5c-7ae9-41e0-8165-755258e64dec}"
    }
  }
}