Examine source code of Replace Text

{
  "manifest_version": 2,
  "name": "R Text",
  "version": "1.1",
  "description": "Replace text on web pages.",
  "icons": {
    "48": "icon/border-48.png"
  },
  "permissions": [
    "tabs",
    "https://*/*",
    "http://*/*",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icon/border-48.png",
    "default_title": "Replace Text",
    "default_popup": "popup/replace.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a65a14fb-d95c-4b82-aec2-1c49618a4425}"
    }
  }
}