Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x134 [BFC] children: not-inline
    BlockContainer <body> at (8,8) content-size 784x118 children: inline
      frag 0 from TextNode start: 1, length: 3, rect: [8,108 27.15625x18] baseline: 13.796875
          "foo"
      BlockContainer <div.a> at (8,8) content-size 100x100 floating [BFC] children: not-inline
      TextNode <#text>
      BreakNode <br.b>
      TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x134]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x118]
      PaintableWithLines (BlockContainer<DIV>.a) [8,8 100x100]
      TextPaintable (TextNode<#text>)
