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

Source/core/rendering/svg/SVGTextRunRenderingContext.cpp

 /*
  * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) Research In Motion Limited 2010-2011. 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,
@@ skipping 52 matching lines @@
     return renderer->isText() ? renderer->parent() : renderer;
 }
 
 static inline RenderObject* renderObjectFromRun(const TextRun& run)
 {
     if (TextRun::RenderingContext* renderingContext = run.renderingContext())
         return static_cast<SVGTextRunRenderingContext*>(renderingContext)->renderer();
     return 0;
 }
 
-float SVGTextRunRenderingContext::floatWidthUsingSVGFont(const Font& font, const TextRun& run, unsigned& charsConsumed, Glyph& glyphId) const
+float SVGTextRunRenderingContext::floatWidthUsingSVGFont(const Font& font, const TextRun& run, int& charsConsumed, Glyph& glyphId) const
 {
     SimpleShaper it(&font, run);
     GlyphBuffer glyphBuffer;
     charsConsumed += it.advance(run.length(), &glyphBuffer);
     glyphId = !glyphBuffer.isEmpty() ? glyphBuffer.glyphAt(0) : 0;
     return it.runWidthSoFar();
 }
 
 void SVGTextRunRenderingContext::drawSVGGlyphs(GraphicsContext* context, const TextRun& run, const SimpleFontData* fontData, const GlyphBuffer& glyphBuffer, int from, int numGlyphs, const FloatPoint& point) const
 {
@@ skipping 136 matching lines @@
     // Restore original state of the SVG Font glyph table and the current font fallback list,
     // to assure the next lookup of the same glyph won't immediately return the fallback glyph.
     page->setGlyphDataForCharacter(character, glyphData.glyph, originalFontData);
     ASSERT(fallbackGlyphData.fontData);
     return fallbackGlyphData;
 }
 
 }
 
 #endif