Move SVGTextMetricsBuilder metrics computation state to a local helper class

Source/core/rendering/svg/SVGTextMetricsBuilder.h

 /*
  * Copyright (C) Research In Motion Limited 2010-2012. 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGTextMetricsBuilder_h
 #define SVGTextMetricsBuilder_h
 
 #include "core/rendering/svg/SVGTextLayoutAttributes.h"
-#include "core/rendering/svg/SVGTextMetrics.h"
-#include "platform/fonts/WidthIterator.h"
-#include "platform/text/TextRun.h"
-#include "wtf/Vector.h"
 
 namespace WebCore {
 
 class RenderObject;
 class RenderSVGInlineText;
 class RenderSVGText;
 struct MeasureTextData;
 
 class SVGTextMetricsBuilder {
     WTF_MAKE_NONCOPYABLE(SVGTextMetricsBuilder);
 public:
-    SVGTextMetricsBuilder();
+    SVGTextMetricsBuilder() { }
+
     void measureTextRenderer(RenderSVGInlineText*);
     void buildMetricsAndLayoutAttributes(RenderSVGText*, RenderSVGInlineText* stopAtLeaf, SVGCharacterDataMap& allCharactersMap);
 
 private:
-    SVGTextMetrics computeMetricsForCurrentCharacter(unsigned textPosition);
-    SVGTextMetrics computeMetricsForCurrentCharacterSimple(unsigned textPosition);
-    SVGTextMetrics computeMetricsForCurrentCharacterComplex(unsigned textPosition);
-    bool currentCharacterStartsSurrogatePair(unsigned textPosition) const;
-
-    void initializeMeasurementWithTextRenderer(RenderSVGInlineText*);
     void walkTree(RenderObject*, RenderSVGInlineText* stopAtLeaf, MeasureTextData*);
     void measureTextRenderer(RenderSVGInlineText*, MeasureTextData*, bool processRenderer);
-
-    RenderSVGInlineText* m_text;
-    TextRun m_run;
-    bool m_isComplexText;
-    float m_totalWidth;
-
-    // Simple text only.
-    OwnPtr<WidthIterator> m_simpleWidthIterator;
 };
 
 } // namespace WebCore
 
 #endif