CASE 1, original layer tree
{
  "layers": [
    {
      "name": "Scrolling background of LayoutView #document",
      "bounds": [800, 600],
      "contentsOpaque": true,
      "backgroundColor": "#FFFFFF"
    },
    {
      "name": "LayoutNGBlockFlow (positioned) DIV class='composited box behind'",
      "bounds": [100, 100],
      "contentsOpaque": true,
      "backgroundColor": "#0000FF",
      "transform": 1
    },
    {
      "name": "LayoutNGBlockFlow (positioned) DIV class='box top'",
      "position": [130, 130],
      "bounds": [100, 100],
      "contentsOpaque": true,
      "backgroundColor": "#00FFFF"
    }
  ],
  "transforms": [
    {
      "id": 1,
      "transform": [
        [1, 0, 0, 0],
        [0, 1, 0, 0],
        [0, 0, 1, 0],
        [50, 50, 0, 1]
      ]
    }
  ]
}

CASE 2, change color of "inner" to red
{
  "layers": [
    {
      "name": "Scrolling background of LayoutView #document",
      "bounds": [800, 600],
      "contentsOpaque": true,
      "backgroundColor": "#FFFFFF"
    },
    {
      "name": "LayoutNGBlockFlow (positioned) DIV class='composited box behind'",
      "bounds": [100, 100],
      "contentsOpaque": true,
      "backgroundColor": "#0000FF",
      "transform": 1
    },
    {
      "name": "LayoutNGBlockFlow (positioned) DIV class='box top'",
      "position": [130, 130],
      "bounds": [100, 100],
      "contentsOpaque": true,
      "backgroundColor": "#00FFFF",
      "invalidations": [
        [10, 10, 50, 50]
      ]
    }
  ],
  "transforms": [
    {
      "id": 1,
      "transform": [
        [1, 0, 0, 0],
        [0, 1, 0, 0],
        [0, 0, 1, 0],
        [50, 50, 0, 1]
      ]
    }
  ]
}