Examine source code of Quick Focus Cleaner

{
  "manifest_version": 2,
  "name": "Quick Focus Cleaner",
  "version": "1.0",
  "description": "Removes focus outlines on mouse click for a cleaner UI.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Toggle Focus Cleaner",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e39383bd-a724-4dd5-ba5b-ec5475fede57}"
    }
  }
}