Revert of TextRun::length() should return an unsigned

Source/core/rendering/svg/SVGTextRunRenderingContext.h

 /*
  * Copyright (C) Research In Motion Limited 2011. 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 23 matching lines @@
     static PassRefPtr<SVGTextRunRenderingContext> create(RenderObject* renderer)
     {
         return adoptRef(new SVGTextRunRenderingContext(renderer));
     }
 
     RenderObject* renderer() const { return m_renderer; }
 
 #if ENABLE(SVG_FONTS)
     virtual GlyphData glyphDataForCharacter(const Font&, const TextRun&, SimpleShaper&, UChar32 character, bool mirror, int currentCharacter, unsigned& advanceLength) override;
     virtual void drawSVGGlyphs(GraphicsContext*, const TextRun&, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const override;
-    virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, unsigned& charsConsumed, Glyph& glyphId) const override;
+    virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, int& charsConsumed, Glyph& glyphId) const override;
 #else
     virtual GlyphData glyphDataForCharacter(const Font&, const TextRun&, SimpleShaper&, UChar32 character, bool mirror, int currentCharacter, unsigned& advanceLength) override { return 0; }
     virtual void drawSVGGlyphs(GraphicsContext*, const TextRun&, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const override { }
-    virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, unsigned& charsConsumed, Glyph& glyphId) const override { return 0; }
+    virtual float floatWidthUsingSVGFont(const Font&, const TextRun&, int& charsConsumed, Glyph& glyphId) const override { return 0; }
 #endif
 
 private:
     SVGTextRunRenderingContext(RenderObject* renderer)
         : m_renderer(renderer)
     {
     }
 
     virtual ~SVGTextRunRenderingContext() { }
 
     RenderObject* m_renderer;
 };
 
 inline bool textRunNeedsRenderingContext(const Font& font)
 {
     // Only save the extra data if SVG Fonts are used, which depend on them.
     // FIXME: SVG Fonts won't work as segmented fonts at the moment, if that's fixed, we need to check for them as well below.
     ASSERT(font.primaryFont());
     return font.primaryFont()->isSVGFont();
 }
 
 } // namespace blink
 
 #endif // SVGTextRunRenderingContext_h