third_party/blink/web_tests/flag-specific/enable-blink-features=CompositeAfterPaint/compositing/layer-tree-expected.txt

Layer tree:
{
  "layers": [
    {
      "name": "Scrolling background of LayoutView #document",
      "bounds": [1200, 900],
      "contentsOpaque": true,
      "backgroundColor": "#FFFFFF"
    },
    {
      "name": "LayoutScrollbarPart (anonymous)",
      "bounds": [800, 600],
      "backgroundColor": "#0000FF"
    }
  ]
}

Layer list
{
  "layers": [
    {
      "name": "Scrolling background of LayoutView #document",
      "bounds": [1200, 900],
      "contentsOpaque": true,
      "backgroundColor": "#FFFFFF"
    },
    {
      "name": "LayoutScrollbarPart (anonymous)",
      "bounds": [800, 600],
      "backgroundColor": "#0000FF"
    }
  ]
}