Examine source code of Send to Popup

{
  "manifest_version": 2,
  "name": "Send to Popup",
  "version": "1.0",
  "description": "Add-on to turn the page into a popup.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "menus",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icon.png"
    },
    "default_title": "Send to Popup"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{affc6c82-3db4-473f-a8fb-fd79ed398b98}"
    }
  }
}