Examine source code of Search Tab Direct

{
  "manifest_version": 2,
  "name": "Search Tab Direct",
  "version": "1.0",
  "description": "The first tab after a google search will take you to the first search result",
  "icons": {
    "48": "icons/SearchTabDirect.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.google.com/*"
      ],
      "js": [
        "tab_first.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ec841a00-2e76-45b8-8120-b45a0311ec05}"
    }
  }
}