Examine source code of EBA Screenshot Extension

{
  "name": "Tab Screenshot Extension",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Take screenshot of selected browser tab.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "screenshot.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{762f7316-d1bc-4711-904e-61bc17ec9410}"
    }
  }
}