Remove superfluous CSSLinearTimingFunctionValue

Source/core/css/CSSComputedStyleDeclaration.cpp

 /*
  * Copyright (C) 2004 Zack Rusin <zack@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2011 Sencha, Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
@@ skipping 1145 matching lines @@
             return cssValuePool().createIdentifierValue(valueId);
         }
         return CSSCubicBezierTimingFunctionValue::create(bezierTimingFunction->x1(), bezierTimingFunction->y1(), bezierTimingFunction->x2(), bezierTimingFunction->y2());
     }
 
     if (timingFunction->isStepsTimingFunction()) {
         const StepsTimingFunction* stepsTimingFunction = static_cast<const StepsTimingFunction*>(timingFunction);
         return CSSStepsTimingFunctionValue::create(stepsTimingFunction->numberOfSteps(), stepsTimingFunction->stepAtStart());
     }
 
-    return CSSLinearTimingFunctionValue::create();
+    return cssValuePool().createIdentifierValue(CSSValueLinear);
 }
 
 static PassRefPtr<CSSValue> valueForAnimationTimingFunction(const CSSAnimationDataList* animList)
 {
     RefPtr<CSSValueList> list = CSSValueList::createCommaSeparated();
     if (animList) {
         for (size_t i = 0; i < animList->size(); ++i)
             list->append(createTimingFunctionValue(animList->animation(i)->timingFunction().get()));
     } else
         // Note that initialAnimationTimingFunction() is used for both transitions and animations
@@ skipping 1976 matching lines @@
     static const CSSPropertyID propertiesAfterSlashSeperator[3] = { CSSPropertyBackgroundSize, CSSPropertyBackgroundOrigin,
                                                                     CSSPropertyBackgroundClip };
 
     RefPtr<CSSValueList> list = CSSValueList::createSlashSeparated();
     list->append(valuesForShorthandProperty(StylePropertyShorthand(CSSPropertyBackground, propertiesBeforeSlashSeperator, WTF_ARRAY_LENGTH(propertiesBeforeSlashSeperator))));
     list->append(valuesForShorthandProperty(StylePropertyShorthand(CSSPropertyBackground, propertiesAfterSlashSeperator, WTF_ARRAY_LENGTH(propertiesAfterSlashSeperator))));
     return list.release();
 }
 
 } // namespace WebCore