Pass start/length at InlineTextBox construction time.

Source/core/rendering/RenderText.h

Index: Source/core/rendering/RenderText.h
diff --git a/Source/core/rendering/RenderText.h b/Source/core/rendering/RenderText.h
index e02afaffa9df801bbef0ad1cfba4c145aa47ad32..9f9d3a5f1fcf2d47ca4fad51d2e694ac713bf879 100644
--- a/Source/core/rendering/RenderText.h
+++ b/Source/core/rendering/RenderText.h
@@ -60,7 +60,7 @@ public:
     virtual unsigned textStartOffset() const { return 0; }
     String plainText() const;
 
-    InlineTextBox* createInlineTextBox();
+    InlineTextBox* createInlineTextBox(int start, unsigned short length);
     void dirtyLineBoxes(bool fullLayout);
 
     virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint& accumulatedOffset) const OVERRIDE FINAL;
@@ -156,7 +156,7 @@ protected:
 
     virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer* currentLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const OVERRIDE;
 
-    virtual InlineTextBox* createTextBox(); // Subclassed by SVG.
+    virtual InlineTextBox* createTextBox(int start, unsigned short length); // Subclassed by SVG.
 
 private:
     void computePreferredLogicalWidths(float leadWidth);