Examine source code of View image size

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "__MSG_app_name__",
  "description": "__MSG_app_description__",
  "version": "1.0.0",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_popup": "popup/popup.html"
  },
  "background": {
    "service_worker": "background.js"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ]
}