Overlay.screenshotRequested

Fired when user asks to capture screenshot of some area on the page.

{
  "name": "screenshotRequested",
  "description": "Fired when user asks to capture screenshot of some area on the page.",
  "parameters": [
    {
      "name": "viewport",
      "$ref": "Page.Viewport",
      "description": "Viewport to capture, in CSS."
    }
  ]
}