Examine source code of Go Up Button

{
  "manifest_version": 2,
  "name": "Go Up",
  "version": "1.1.1resigned1",
  "description": "Adds a Go Up (parent) button for Firefox",
  "icons": {
    "48": "icons/main_icon.svg",
    "96": "icons/main_icon.svg"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "browser_style": true,
    "default_title": "Go Up",
    "theme_icons": [
      {
        "dark": "icons/ic_arrow_upward_black_48px.svg",
        "light": "icons/ic_arrow_upward_white_48px.svg",
        "size": 48
      },
      {
        "dark": "icons/ic_arrow_upward_black_48px.svg",
        "light": "icons/ic_arrow_upward_white_48px.svg",
        "size": 96
      }
    ]
  },
  "background": {
    "scripts": [
      "goup.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{080395d5-2f2d-44ff-8320-79747016b5d4}"
    }
  }
}