CSSValue Immediates: Replace CSSPrimitiveValue usage with const references

Source/core/animation/StringKeyframe.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/animation/StringKeyframe.h"
 
 #include "core/animation/AngleSVGInterpolation.h"
 #include "core/animation/CSSValueInterpolationType.h"
 #include "core/animation/ColorStyleInterpolation.h"
@@ skipping 88 matching lines @@
     ASSERT(property.isSVGAttribute());
     return adoptPtrWillBeNoop(new SVGPropertySpecificKeyframe(offset(), &easing(), svgPropertyValue(*property.svgAttribute()), composite()));
 }
 
 DEFINE_TRACE(StringKeyframe)
 {
     visitor->trace(m_propertySet);
     Keyframe::trace(visitor);
 }
 
-StringKeyframe::CSSPropertySpecificKeyframe::CSSPropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, NullableCSSValue value, EffectModel::CompositeOperation op)
+StringKeyframe::CSSPropertySpecificKeyframe::CSSPropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, const NullableCSSValue& value, EffectModel::CompositeOperation op)
     : Keyframe::PropertySpecificKeyframe(offset, easing, op)
     , m_value(value)
 { }
 
-StringKeyframe::CSSPropertySpecificKeyframe::CSSPropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, NullableCSSValue value)
+StringKeyframe::CSSPropertySpecificKeyframe::CSSPropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, const NullableCSSValue& value)
     : Keyframe::PropertySpecificKeyframe(offset, easing, EffectModel::CompositeReplace)
     , m_value(value)
 {
     ASSERT(!isNull(m_offset));
 }
 
 void StringKeyframe::CSSPropertySpecificKeyframe::populateAnimatableValue(CSSPropertyID property, Element& element, const ComputedStyle* baseStyle) const
 {
     if (!m_animatableValueCache && (baseStyle || !DeferredLegacyStyleInterpolation::interpolationRequiresStyleResolve(*m_value)))
         m_animatableValueCache = StyleResolver::createAnimatableValueSnapshot(element, baseStyle, property, m_value);
@@ skipping 62 matching lines @@
     NullableCSSValue nullableToCSSValue = toCSSPropertySpecificKeyframe(end).value();
     InterpolationRange range = RangeAll;
     bool fallBackToLegacy = false;
 
     // FIXME: Remove this flag once we can rely on legacy's behaviour being correct.
     bool forceDefaultInterpolation = false;
 
     // FIXME: Remove this check once neutral keyframes are implemented in StringKeyframes.
     if (!nullableFromCSSValue || !nullableToCSSValue)
         return DeferredLegacyStyleInterpolation::create(nullableFromCSSValue, nullableToCSSValue, property);
-    CSSValue& fromCSSValue = *nullableFromCSSValue;
-    CSSValue& toCSSValue = *nullableToCSSValue;
+    const CSSValue& fromCSSValue = *nullableFromCSSValue;
+    const CSSValue& toCSSValue = *nullableToCSSValue;
 
     if (!CSSPropertyMetadata::isInterpolableProperty(property)) {
         if (fromCSSValue.ptrEquals(toCSSValue))
             return ConstantStyleInterpolation::create(fromCSSValue, property);
 
         return nullptr;
     }
 
     switch (property) {
     case CSSPropertyLineHeight:
@@ skipping 389 matching lines @@
     RefPtrWillBeRawPtr<SVGPropertyBase> fromValue = attribute->currentValueBase()->cloneForAnimation(m_value);
     RefPtrWillBeRawPtr<SVGPropertyBase> toValue = attribute->currentValueBase()->cloneForAnimation(toSVGPropertySpecificKeyframe(end).value());
 
     if (!fromValue || !toValue)
         return nullptr;
 
     return createSVGInterpolation(fromValue.get(), toValue.get(), attribute.get());
 }
 
 } // namespace blink