AccumulatedVisualContext Tree:
  [0] transform=[1,0,0,1,0,0] origin=(0,0) (ViewportPaintable(Viewport<#document>))
    [1] scroll (PaintableWithLines(BlockContainer<PRE>#out))
      [2] clip=[8,8 100x100]
        [3] mask=[-2,-2 119x119] kind=luminance origin=svg-mask (SVGForeignObjectPaintable(SVGForeignObjectBox<foreignObject>#fo))
          [4] clip=[9,8 100x100] (PaintableWithLines(BlockContainer(anonymous)))

DisplayList:
SaveLayer@0
  CompositorWheelHitTestTarget@0 target_scroll_node_index=0 rect=[0,0 800x600]
  CompositorWheelHitTestTarget@1 target_scroll_node_index=0 rect=[0,0 800x121]
  CompositorWheelHitTestTarget@1 target_scroll_node_index=0 rect=[8,8 784x100]
  CompositorWheelHitTestTarget@1 target_scroll_node_index=0 rect=[8,8 784x100]
  CompositorWheelHitTestTarget@1 target_scroll_node_index=0 rect=[8,8 100x100]
  CompositorWheelHitTestTarget@3 target_scroll_node_index=0 rect=[9,8 100x100]
  CompositorWheelHitTestTarget@4 target_scroll_node_index=0 rect=[9,8 100x100]
  FillRect@4 rect=[9,8 100x100] color=rgb(0, 0, 0)
Restore@0
MaskDisplayList for context 3:
  FillPath@0 path_bounding_rect=[8,8 100x100]

