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  RenderView at (0,0) size 800x600
layer at (0,0) size 800x600
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    RenderBody {BODY} at (8,8) size 784x584
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        RenderText {#text} at (0,0) size 159x18
          text run at (0,0) width 159: "Test x-height caluclation."
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          text run at (0,0) width 243: "This box is 5ex by 5ex at 100px Arial."
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