Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
    BlockContainer <body> at (8,8) content-size 784x150 children: inline
      frag 0 from ImageBox start: 0, length: 0, rect: [8,8 300x150] baseline: 150
      ImageBox <img> at (8,8) content-size 300x150 children: not-inline
        (SVG-as-image isolated context)
        Viewport <#document> at (0,0) content-size 300x150 [BFC] children: not-inline
          SVGSVGBox <svg> at (0,0) content-size 300x150 [SVG] children: not-inline

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x150]
      ImagePaintable (ImageBox<IMG>) [8,8 300x150]
