Custom Shortcut Button

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Custom Shortcut Button",
  "short_name": "Custom Shortcut",
  "description": "Allows you to set a custom shortcut button next to your address bar.",
  "version": "1.0",
  "version_name": "1.0",
  "minimum_chrome_version": "38",
  "icons": {
    "16": "assets/icon.png",
    "48": "assets/icon.png",
    "128": "assets/icon.png",
    "512": "assets/icon.png"
  },
  "browser_action": {
    "default_icon": "assets/icon.png",
    "default_title": ""
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "index.html"
  }
}