[SVG] Make metrics passed to calculateGlyphAdvanceAndOrientation const

Source/core/rendering/svg/SVGTextLayoutEngineBaseline.cpp

 /*
  * Copyright (C) Research In Motion Limited 2010. 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 160 matching lines @@
     default:
         return 0;
     }
 }
 
 static inline bool glyphOrientationIsMultiplyOf180Degrees(float orientationAngle)
 {
     return !fabsf(fmodf(orientationAngle, 180));
 }
 
-float SVGTextLayoutEngineBaseline::calculateGlyphAdvanceAndOrientation(bool isVerticalText, SVGTextMetrics& metrics, float angle, float& xOrientationShift, float& yOrientationShift) const
+float SVGTextLayoutEngineBaseline::calculateGlyphAdvanceAndOrientation(bool isVerticalText, const SVGTextMetrics& metrics, float angle, float& xOrientationShift, float& yOrientationShift) const
 {
     bool orientationIsMultiplyOf180Degrees = glyphOrientationIsMultiplyOf180Degrees(angle);
 
     // The function is based on spec requirements:
     //
     // Spec: If the 'glyph-orientation-horizontal' results in an orientation angle that is not a multiple of
     // of 180 degrees, then the current text position is incremented according to the vertical metrics of the glyph.
     //
     // Spec: If if the 'glyph-orientation-vertical' results in an orientation angle that is not a multiple of
     // 180 degrees, then the current text position is incremented according to the horizontal metrics of the glyph.
@@ skipping 30 matching lines @@
         xOrientationShift = metrics.width();
 
     // Horizontal advance calculation.
     if (angle && !orientationIsMultiplyOf180Degrees)
         return metrics.height();
 
     return metrics.width();
 }
 
 }