Keep text position locally in SVGTextMetricsBuilder::measureTextRenderer

Source/core/rendering/svg/SVGTextMetricsBuilder.h

Index: Source/core/rendering/svg/SVGTextMetricsBuilder.h
diff --git a/Source/core/rendering/svg/SVGTextMetricsBuilder.h b/Source/core/rendering/svg/SVGTextMetricsBuilder.h
index 708f10323f7f836727a34833881a409242230c9d..0ad2710c0b3a30ac0fda96830e46c2d2ce89c962 100644
--- a/Source/core/rendering/svg/SVGTextMetricsBuilder.h
+++ b/Source/core/rendering/svg/SVGTextMetricsBuilder.h
@@ -41,10 +41,10 @@ public:
     void buildMetricsAndLayoutAttributes(RenderSVGText*, RenderSVGInlineText* stopAtLeaf, SVGCharacterDataMap& allCharactersMap);
 
 private:
-    SVGTextMetrics computeMetricsForCurrentCharacter();
-    SVGTextMetrics computeMetricsForCurrentCharacterSimple();
-    SVGTextMetrics computeMetricsForCurrentCharacterComplex();
-    bool currentCharacterStartsSurrogatePair() const;
+    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*);
@@ -52,7 +52,6 @@ private:
 
     RenderSVGInlineText* m_text;
     TextRun m_run;
-    unsigned m_textPosition;
     bool m_isComplexText;
     float m_totalWidth;