AccumulatedVisualContext Tree:
  [1] scroll_frame_id=1 (PaintableWithLines(BlockContainer<PRE>#out))
    [2] clip=[10,10 200x100]
      [3] scroll_frame_id=2 (PaintableWithLines(BlockContainer<DIV>.inner-box))

DisplayList:
SaveLayer@0
  CompositorWheelHitTestTarget@0 target_scroll_frame_index=0 rect=[0,0 800x600]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[0,0 800x125]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[8,8 784x104]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[8,8 204x104]
  FillPath@1 path_bounding_rect=[8,8 204x104]
  CompositorWheelHitTestTarget@3 target_scroll_frame_index=0 rect=[10,10 300x150]
  FillRect@3 rect=[10,10 300x150] color=rgb(240, 128, 128)
  DrawGlyphRun@3 rect=[10,10 38x18] translation=[10,23.796875] color=rgb(0, 0, 0)
Restore@0