Layer tree:
{
  "name": "Root Transform Layer",
  "drawsContent": false,
  "children": [
    {
      "name": "Inner Viewport Container Layer",
      "bounds": [800, 600],
      "drawsContent": false,
      "children": [
        {
          "name": "Page Scale Layer",
          "drawsContent": false,
          "children": [
            {
              "name": "Inner Viewport Scroll Layer",
              "bounds": [800, 600],
              "drawsContent": false,
              "children": [
                {
                  "name": "LayoutView #document",
                  "bounds": [800, 600],
                  "drawsContent": false,
                  "backgroundColor": "#FFFFFF",
                  "shouldFlattenTransform": false,
                  "children": [
                    {
                      "name": "Scrolling Layer",
                      "bounds": [780, 580],
                      "drawsContent": false,
                      "flattenInheritedTransform": false,
                      "shouldFlattenTransform": false,
                      "children": [
                        {
                          "name": "Scrolling Contents Layer",
                          "bounds": [1200, 900],
                          "contentsOpaque": true,
                          "backgroundColor": "#FFFFFF",
                          "flattenInheritedTransform": false
                        }
                      ]
                    }
                  ]
                }
              ]
            }
          ]
        },
        {
          "name": "Overflow Controls Host Layer",
          "bounds": [800, 600],
          "drawsContent": false,
          "children": [
            {
              "name": "Horizontal Scrollbar Layer",
              "position": [0, 580],
              "bounds": [780, 20]
            },
            {
              "name": "Vertical Scrollbar Layer",
              "position": [780, 0],
              "bounds": [20, 580]
            },
            {
              "name": "Scroll Corner Layer",
              "position": [780, 580],
              "bounds": [20, 20]
            }
          ]
        }
      ]
    }
  ]
}

Layer list
{
  "layers": [
    {
      "name": "Root Transform Layer",
      "drawsContent": false
    },
    {
      "name": "Inner Viewport Container Layer",
      "bounds": [800, 600],
      "drawsContent": false
    },
    {
      "name": "Page Scale Layer",
      "drawsContent": false
    },
    {
      "name": "Inner Viewport Scroll Layer",
      "bounds": [800, 600],
      "drawsContent": false
    },
    {
      "name": "LayoutView #document",
      "bounds": [800, 600],
      "drawsContent": false,
      "backgroundColor": "#FFFFFF"
    },
    {
      "name": "Scrolling Layer",
      "bounds": [780, 580],
      "drawsContent": false
    },
    {
      "name": "Scrolling Contents Layer",
      "bounds": [1200, 900],
      "contentsOpaque": true,
      "backgroundColor": "#FFFFFF"
    },
    {
      "name": "Overflow Controls Host Layer",
      "bounds": [800, 600],
      "drawsContent": false
    },
    {
      "name": "Horizontal Scrollbar Layer",
      "position": [0, 580],
      "bounds": [780, 20]
    },
    {
      "name": "Vertical Scrollbar Layer",
      "position": [780, 0],
      "bounds": [20, 580]
    },
    {
      "name": "Scroll Corner Layer",
      "position": [780, 580],
      "bounds": [20, 20]
    }
  ]
}