Don't iterate past the end of the metrics list

Source/core/layout/svg/LayoutSVGInlineText.h

 /*
  * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Rob Buis <buis@kde.org>
  *
  * 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.
  *
@@ skipping 88 matching lines @@
     }
 
     const SVGTextMetrics& metrics() const
     {
         ASSERT(m_textLayoutObject && m_metricsListOffset < metricsList().size());
         return metricsList()[m_metricsListOffset];
     }
     const Vector<SVGTextMetrics>& metricsList() const { return m_textLayoutObject->layoutAttributes()->textMetricsValues(); }
     unsigned metricsListOffset() const { return m_metricsListOffset; }
     unsigned characterOffset() const { return m_characterOffset; }
+    bool isAtEnd() const { return m_metricsListOffset == metricsList().size(); }
 
 private:
     void reset(const LayoutSVGInlineText* textLayoutObject)
     {
         m_textLayoutObject = textLayoutObject;
         m_characterOffset = 0;
         m_metricsListOffset = 0;
     }
 
     const LayoutSVGInlineText* m_textLayoutObject;
     unsigned m_metricsListOffset;
     unsigned m_characterOffset;
 };
 
 }
 
 #endif // LayoutSVGInlineText_h