Examine source code of Theme Switcher for eA

{
  "manifest_version": 2,
  "name": "Theme Switcher",
  "version": "1.0",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6b31ab73-521a-40ea-b8c5-a7a94a9fd77f}"
    }
  }
}