preventing the browser back action

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "preventing the browser back action",
  "version": "0.1.1",
  "author": "Okita Kamegoro",
  "browser_action": {
    "default_icon": "./img/undo-blue.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "128": "./img/undo-blue.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "contents_script.js"
      ]
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "description": "preventing the browser back action",
  "short_name": "preventing the browser back action"
}