Move most of the [Pass]RefPtr's of CSSPrimitiveValue to our transition types.

Source/core/animation/AnimatableLength.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 137 matching lines @@
 static bool isCompatibleWithRange(const CSSPrimitiveValue* primitiveValue, NumberRange range)
 {
     ASSERT(primitiveValue);
     if (range == AllValues)
         return true;
     if (primitiveValue->isCalculated())
         return primitiveValue->cssCalcValue()->permittedValueRange() == ValueRangeNonNegative;
     return primitiveValue->getDoubleValue() >= 0;
 }
 
-PassRefPtr<CSSPrimitiveValue> AnimatableLength::toCSSPrimitiveValue(NumberRange range) const
+PassRefPtrWillBeRawPtr<CSSPrimitiveValue> AnimatableLength::toCSSPrimitiveValue(NumberRange range) const
 {
     if (!m_cachedCSSPrimitiveValue || !isCompatibleWithRange(m_cachedCSSPrimitiveValue.get(), range)) {
         if (isCalc())
             m_cachedCSSPrimitiveValue = CSSPrimitiveValue::create(CSSCalcValue::create(m_calcExpression, range == AllValues ? ValueRangeAll : ValueRangeNonNegative));
         else
             m_cachedCSSPrimitiveValue = CSSPrimitiveValue::create(clampedNumber(range), static_cast<CSSPrimitiveValue::UnitTypes>(numberTypeToPrimitiveUnit(m_unitType)));
     }
     return m_cachedCSSPrimitiveValue;
 }
 
@@ skipping 70 matching lines @@
     case UnitTypeViewportMax:
         return CSSPrimitiveValue::CSS_VMAX;
     case UnitTypeCalc:
         return CSSPrimitiveValue::CSS_UNKNOWN;
     }
     ASSERT_NOT_REACHED();
     return CSSPrimitiveValue::CSS_UNKNOWN;
 }
 
 } // namespace WebCore