Examine source code of Unhide

{
  "manifest_version": 2,
  "name": "Unhide",
  "version": "1.0",
  "description": "Shows all hidden elements.",
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png"
    },
    "default_title": "Unhide",
    "default_popup": "menu.html",
    "theme_icons": [
      {
        "light": "icons/icon16.png",
        "dark": "icons/icon16.png",
        "size": 16
      },
      {
        "light": "icons/icon32.png",
        "dark": "icons/icon32.png",
        "size": 32
      }
    ]
  }
}