Examine source code of Copy Opaque Image

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "applications": {
    "gecko": {
      "id": "copy-opaque-image@qw.thucfb.com"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "menus",
    "<all_urls>",
    "clipboardWrite"
  ],
  "version": "1.1resigned1",
  "default_locale": "en"
}