Examine source code of Clear Cache & Close Tabs

{
  "manifest_version": 2,
  "name": "Clear Cache & Close Tabs",
  "version": "3.0",
  "description": "An extension to clear browser cache and close all tabs.",
  "permissions": [
    "browsingData",
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "clearcache@example.com"
    }
  }
}