Examine source code of Tab To Play

{
  "manifest_version": 2,
  "name": "Tab To Play",
  "description": "TabToPlay.net transforms your new tab with easy access to popular gaming sites and sets Yahoo as your search engine for a smooth browsing experience.",
  "version": "1.0.0.0",
  "background": {
    "scripts": [
      "bgw/constants.js",
      "bgw/utility.js",
      "bgw/background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "128": "logos/logo128.png"
    },
    "default_title": "Tab To Play"
  },
  "icons": {
    "16": "logos/logo16.png",
    "32": "logos/logo32.png",
    "48": "logos/logo48.png",
    "128": "logos/logo128.png"
  },
  "permissions": [
    "storage",
    "contextMenus"
  ],
  "chrome_url_overrides": {
    "newtab": "widget/newtab.html"
  },
  "chrome_settings_overrides": {
    "search_provider": {
      "name": "Tab To Play",
      "keyword": "TabToPlay",
      "suggest_url": "https://search.yahoo.com/sugg/ie?output=fxjson&command={searchTerms}&nResults=12",
      "favicon_url": "https://tabtoplay.net/favicon.png",
      "search_url": "https://search.yahoo.com/search?q={searchTerms}",
      "encoding": "UTF-8",
      "is_default": true
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{447c5140-aede-4b63-ba42-834bb9c902f3}"
    }
  }
}