Make PropertyHandle instances const references where possible

third_party/WebKit/Source/core/animation/animatable/AnimatableValueKeyframe.h

 // 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.
 
 #ifndef AnimatableValueKeyframe_h
 #define AnimatableValueKeyframe_h
 
 #include "core/CoreExport.h"
 #include "core/animation/Keyframe.h"
 #include "core/animation/animatable/AnimatableValue.h"
@@ skipping 33 matching lines @@
     AnimatableValue* value() const { return m_value.get(); }
     PassRefPtr<AnimatableValue> getAnimatableValue() const final {
       return m_value;
     }
 
     bool isNeutral() const final { return m_value->isNeutral(); }
     PassRefPtr<Keyframe::PropertySpecificKeyframe> neutralKeyframe(
         double offset,
         PassRefPtr<TimingFunction> easing) const final;
     PassRefPtr<Interpolation> createInterpolation(
-        PropertyHandle,
+        const PropertyHandle&,
         const Keyframe::PropertySpecificKeyframe& end) const final;
 
    private:
     PropertySpecificKeyframe(double offset,
                              PassRefPtr<TimingFunction> easing,
                              PassRefPtr<AnimatableValue> value,
                              EffectModel::CompositeOperation composite)
         : Keyframe::PropertySpecificKeyframe(offset,
                                              std::move(easing),
                                              composite),
           m_value(value) {}
 
     PassRefPtr<Keyframe::PropertySpecificKeyframe> cloneWithOffset(
         double offset) const override;
     bool isAnimatableValuePropertySpecificKeyframe() const override {
       return true;
     }
 
     RefPtr<AnimatableValue> m_value;
   };
 
  private:
   AnimatableValueKeyframe() {}
 
   AnimatableValueKeyframe(const AnimatableValueKeyframe& copyFrom);
 
   PassRefPtr<Keyframe> clone() const override;
   PassRefPtr<Keyframe::PropertySpecificKeyframe> createPropertySpecificKeyframe(
-      PropertyHandle) const override;
+      const PropertyHandle&) const override;
 
   bool isAnimatableValueKeyframe() const override { return true; }
 
   using PropertyValueMap = HashMap<CSSPropertyID, RefPtr<AnimatableValue>>;
   PropertyValueMap m_propertyValues;
 };
 
 using AnimatableValuePropertySpecificKeyframe =
     AnimatableValueKeyframe::PropertySpecificKeyframe;
 
 DEFINE_TYPE_CASTS(AnimatableValueKeyframe,
                   Keyframe,
                   value,
                   value->isAnimatableValueKeyframe(),
                   value.isAnimatableValueKeyframe());
 DEFINE_TYPE_CASTS(AnimatableValuePropertySpecificKeyframe,
                   Keyframe::PropertySpecificKeyframe,
                   value,
                   value->isAnimatableValuePropertySpecificKeyframe(),
                   value.isAnimatableValuePropertySpecificKeyframe());
 
 }  // namespace blink
 
 #endif