Clamp, not cast length value in CSS length conversion

third_party/WebKit/Source/core/css/CSSPrimitiveValue.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2012 Apple Inc. 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 390 matching lines @@
     return roundForImpreciseConversion<short>(computeLengthDouble(conversionData));
 }
 
 template<> unsigned short CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
 {
     return roundForImpreciseConversion<unsigned short>(computeLengthDouble(conversionData));
 }
 
 template<> float CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
 {
-    return static_cast<float>(computeLengthDouble(conversionData));
+    return clampTo<float>(computeLengthDouble(conversionData));
 }
 
 template<> double CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
 {
     return computeLengthDouble(conversionData);
 }
 
 double CSSPrimitiveValue::computeLengthDouble(const CSSToLengthConversionData& conversionData) const
 {
     if (type() == UnitType::Calc)
@@ skipping 412 matching lines @@
     case UnitType::Calc:
         visitor->trace(m_value.calc);
         break;
     default:
         break;
     }
     CSSValue::traceAfterDispatch(visitor);
 }
 
 } // namespace blink