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 784x22 children: inline
      frag 0 from BlockContainer start: 0, length: 0, rect: [8,13 300x12] baseline: 12
      BlockContainer <progress#a> at (8,13) content-size 300x12 inline-block [BFC] children: not-inline
        BlockContainer <div> at (9,14) content-size 298x12 children: not-inline
          BlockContainer <div> at (9,14) content-size 298x12 children: not-inline
      TextNode <#text>
      TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x22]
      PaintableWithLines (BlockContainer<PROGRESS>#a) [8,13 300x12] overflow: [8,13 300x14]
        PaintableWithLines (BlockContainer<DIV>) [8,13 300x14]
          PaintableWithLines (BlockContainer<DIV>) [9,14 298x12]
