Examine source code of Browser Lock Simple

{
  "manifest_version": 2,
  "name": "Browser Lock",
  "version": "1.1",
  "description": "Lock/unlock browser input with a single click",
  "permissions": [
    "<all_urls>",
    "webNavigation",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "browser-lock@yourdomain.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_icon": {
      "16": "icon-16-unlocked.png",
      "32": "icon-32-unlocked.png",
      "48": "icon-48-unlocked.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start"
    }
  ],
  "icons": {
    "48": "icon-48-unlocked.png",
    "96": "icon-96-unlocked.png"
  }
}