When the parent document becomes composited, the layer trees should get connected together.
{
"layers": [
{
"name": "Scrolling background of LayoutView #document",
"bounds": [800, 600],
"contentsOpaque": true,
"backgroundColor": "#FFFFFF"
},
{
"name": "Scrolling background of LayoutView #document",
"bounds": [285, 230],
"contentsOpaque": true,
"backgroundColor": "#C0C0C0",
"transform": 1
},
{
"name": "LayoutBlockFlow DIV id='iframe-content' class='box'",
"bounds": [210, 210],
"contentsOpaque": true,
"backgroundColor": "#0000FF",
"transform": 2
},
{
"name": "VerticalScrollbar",
"position": [285, 0],
"bounds": [15, 150],
"contentsOpaque": true,
"transform": 1
},
{
"name": "LayoutBlockFlow DIV id='box' class='composited'",
"bounds": [100, 100],
"contentsOpaque": true,
"backgroundColor": "#0000FF",
"transform": 3
}
],
"transforms": [
{
"id": 1,
"transform": [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[43, 143, 0, 1]
]
},
{
"id": 2,
"parent": 1,
"transform": [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[18, 10, 0, 1]
]
},
{
"id": 3,
"transform": [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[8, 8, 0, 1]
]
}
]
}