layer at (0,0) size 800x600
  RenderView 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
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        text run at (0,0) width 760: "This is a test to make sure rem units used on the root element"
        text run at (0,37) width 458: "are relative to the user agent default."