Examine source code of Toggle Switch

{
  "description": "A dropdown to toggle a switch",
  "manifest_version": 2,
  "name": "Toggle Switch",
  "version": "1.1.3",
  "icons": {
    "48": "static_contents/PrxRecExt/PrxRecExt.png",
    "96": "static_contents/PrxRecExt/PrxRecExt@2x.png",
    "128": "static_contents/PrxRecExt/PrxRecExt_128.png"
  },
  "permissions": [
    "activeTab",
    "<all_urls>",
    "tabs",
    "cookies",
    "browsingData",
    "proxy"
  ],
  "browser_action": {
    "default_icon": {
      "16": "static_contents/PrxRecExt1_black_16/PrxRecExt1_black_16.png",
      "32": "static_contents/PrxRecExt1_black_16/PrxRecExt1_black_16@2x.png",
      "64": "static_contents/PrxRecExt1_black_16/PrxRecExt1_black_16@3x.png"
    },
    "default_title": "Toggle Switch",
    "default_popup": "popup/choose_action.html"
  }
}