[SVG] Fix root element length values handling.

Source/core/svg/SVGLengthContext.h

 /*
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 48 matching lines @@
         return SVGLengthContext::resolveRectangle(context, type, viewport, context->xCurrentValue(), context->yCurrentValue(), context->widthCurrentValue(), context->heightCurrentValue());
     }
 
     static FloatRect resolveRectangle(const SVGElement*, SVGUnitTypes::SVGUnitType, const FloatRect& viewport, const SVGLength& x, const SVGLength& y, const SVGLength& width, const SVGLength& height);
     static FloatPoint resolvePoint(const SVGElement*, SVGUnitTypes::SVGUnitType, const SVGLength& x, const SVGLength& y);
     static float resolveLength(const SVGElement*, SVGUnitTypes::SVGUnitType, const SVGLength&);
 
     float convertValueToUserUnits(float, SVGLengthMode, SVGLengthType fromUnit, ExceptionState&) const;
     float convertValueFromUserUnits(float, SVGLengthMode, SVGLengthType toUnit, ExceptionState&) const;
 
-    bool determineViewport(float& width, float& height) const;
+    bool determineViewport(FloatSize&) const;
 
 private:
     SVGLengthContext(const SVGElement*, const FloatRect& viewport);
 
     float convertValueFromUserUnitsToPercentage(float value, SVGLengthMode, ExceptionState&) const;
     float convertValueFromPercentageToUserUnits(float value, SVGLengthMode, ExceptionState&) const;
 
     float convertValueFromUserUnitsToEMS(float value, ExceptionState&) const;
     float convertValueFromEMSToUserUnits(float value, ExceptionState&) const;
 
     float convertValueFromUserUnitsToEXS(float value, ExceptionState&) const;
     float convertValueFromEXSToUserUnits(float value, ExceptionState&) const;
 
     const SVGElement* m_context;
     FloatRect m_overridenViewport;
 };
 
 } // namespace WebCore
 
 #endif // SVGLengthContext_h