Examine source code of ReturnToSearch

{
  "manifest_version": 2,
  "name": "BackToSearch",
  "version": "1.1resigned1",
  "description": "returns to most recent search page.",
  "icons": {
    "48": "icons/back-to-search-48.png",
    "96": "icons/back-to-search-96.png"
  },
  "permissions": [
    "activeTab",
    "history"
  ],
  "browser_action": {
    "default_icon": "icons/back-to-search-32.png",
    "default_title": "Return to Search",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "backToSearch.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{43d35275-a0a2-4a7a-a674-ff4feaa90b9d}"
    }
  }
}