Examine source code of Vertigo Magnifier

{
  "manifest_version": 2,
  "name": "Vertigo Magnifier",
  "description": "Zoom video/image with shift+wheel",
  "version": "2.1.1",
  "author": "sodomygnom",
  "icons": {
    "48": "icons/vertigo_48.png",
    "96": "icons/vertigo_96.png"
  },
  "browser_action": {
    "default_icon": "icons/vertigo_96.png",
    "default_title": "Vertigo Magnifier",
    "default_popup": "popup/settings.html"
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "<all_urls>",
    "contextMenus"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{63b80981-fc98-4782-8741-5f4958100943}",
      "strict_min_version": "59.0"
    }
  }
}