AccumulatedVisualContext Tree:
  [1] scroll_frame_id=1 (PaintableWithLines(BlockContainer<PRE>#out))
    [3] clip=[119,9 100x100]
      [4] scroll_frame_id=2 (PaintableWithLines(BlockContainer(anonymous)))
    [2] transform=[1,0,0,1,5,5] origin=(58,58) (PaintableWithLines(BlockContainer<DIV>.transformed))

DisplayList:
SaveLayer@0
  CompositorWheelHitTestTarget@0 target_scroll_frame_index=0 rect=[0,0 800x600]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[0,0 800x123]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[8,8 784x102]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[8,8 784x102]
  CompositorWheelHitTestTarget@1 target_scroll_frame_index=0 rect=[118,8 102x102]
  FillPath@1 path_bounding_rect=[118,8 102x102]
  CompositorWheelHitTestTarget@4 target_scroll_frame_index=0 rect=[119,9 150x150]
  FillRect@4 rect=[119,9 150x150] color=rgb(173, 216, 230)
  DrawGlyphRun@4 rect=[119,9 55x18] translation=[119,22.796875] color=rgb(0, 0, 0)
  CompositorWheelHitTestTarget@2 target_scroll_frame_index=0 rect=[8,8 100x100]
  FillRect@2 rect=[8,8 100x100] color=rgb(255, 127, 80)
  DrawGlyphRun@2 rect=[8,8 88x18] translation=[8,21.796875] color=rgb(0, 0, 0)
Restore@0