layer at (0,0) size 800x600
  RenderCanvas at (0,0) size 800x600
layer at (0,0) size 800x600
  RenderBlock {HTML} at (0,0) size 800x600
    RenderBody {BODY} at (8,8) size 784x584
      RenderBlock {DIV} at (0,0) size 784x84 [border: (2px solid #FF0000)]
        RenderInline {SPAN} at (0,0) size 44x56
          RenderBR {BR} at (14,14) size 0x28
          RenderText {TEXT} at (14,42) size 44x28
            text run at (14,42) width 44: "xfoo"
        RenderText {TEXT} at (0,0) size 0x0
selection is CARET:
start:      position 1 of child 2 {TEXT} of child 2 {SPAN} of root {DIV}
upstream:   position 1 of child 2 {TEXT} of child 2 {SPAN} of root {DIV}
downstream: position 1 of child 2 {TEXT} of child 2 {SPAN} of root {DIV}
