Examine source code of Force RTL

{
  "manifest_version": 2,
  "name": "Force RTL / LTR Toggle",
  "version": "2.0",
  "description": "تبديل اتجاه الصفحة بين اليمين واليسار بنقرة واحدة.",
  "icons": {
    "48": "icon_double_arrow.png"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icon_double_arrow.png"
    },
    "default_title": "Toggle Page Direction (RTL / LTR)"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{151d64ea-e8ea-4c20-b296-096ee4306921}"
    }
  }
}