Examine source code of Joseph Joestar errors

{
  "name": "Joseph Joestar errors",
  "description": "Jojo reacts to browser errors",
  "short_name": "Jojo errors",
  "version": "1.1",
  "manifest_version": 2,
  "permissions": [
    "webNavigation"
  ],
  "background": {
    "scripts": [
      "common.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "jj 32.png",
    "default_title": "Settings",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "jj 16.png",
    "48": "jj 48.png",
    "128": "jj 128.png",
    "256": "jj 256.png"
  }
}