CSSValue Immediates: Replace CSSValue usage with const references

Source/core/animation/LengthBoxStyleInterpolation.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/LengthBoxStyleInterpolation.h"
 
 #include "core/css/resolver/StyleBuilder.h"
 
 namespace blink {
 
 namespace {
 
 bool onlyInterpolateBetweenLengthAndCSSValueAuto(Rect& startRect, Rect& endRect)
 {
     return startRect.left()->isLength() != endRect.left()->isLength()
         && startRect.right()->isLength() != endRect.right()->isLength()
         && startRect.top()->isLength() != endRect.top()->isLength()
         && startRect.bottom()->isLength() != endRect.bottom()->isLength();
 }
 
 } // namespace
 
-PassRefPtrWillBeRawPtr<LengthBoxStyleInterpolation> LengthBoxStyleInterpolation::maybeCreateFrom(CSSValue& start, CSSValue& end, CSSPropertyID id)
+PassRefPtrWillBeRawPtr<LengthBoxStyleInterpolation> LengthBoxStyleInterpolation::maybeCreateFrom(const CSSValue& start, const CSSValue& end, CSSPropertyID id)
 {
     bool startRect = start.isPrimitiveValue() && toCSSPrimitiveValue(start).isRect();
     bool endRect = end.isPrimitiveValue() && toCSSPrimitiveValue(end).isRect();
 
     if (startRect && endRect)
         return adoptRefWillBeNoop(new LengthBoxStyleInterpolation(lengthBoxtoInterpolableValue(start, end, false), lengthBoxtoInterpolableValue(end, start, true), id, start, end));
     return nullptr;
 }
 
 PassOwnPtrWillBeRawPtr<InterpolableValue> LengthBoxStyleInterpolation::lengthBoxtoInterpolableValue(const CSSValue& lengthBox, const CSSValue& matchingValue, bool isEndInterpolation)
@@ skipping 69 matching lines @@
 }
 
 DEFINE_TRACE(LengthBoxStyleInterpolation)
 {
     StyleInterpolation::trace(visitor);
     visitor->trace(m_startCSSValue);
     visitor->trace(m_endCSSValue);
 }
 
 }