Make PropertyHandle instances const references where possible

third_party/WebKit/Source/core/animation/KeyframeEffectModel.h

 /*
  * 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 65 matching lines @@
 
   bool isReplaceOnly();
 
   PropertyHandleSet properties() const;
 
   using KeyframeVector = Vector<RefPtr<Keyframe>>;
   const KeyframeVector& getFrames() const { return m_keyframes; }
   void setFrames(KeyframeVector& keyframes);
 
   const PropertySpecificKeyframeVector& getPropertySpecificKeyframes(
-      PropertyHandle property) const {
+      const PropertyHandle& property) const {
     ensureKeyframeGroups();
     return m_keyframeGroups->get(property)->keyframes();
   }
 
   using KeyframeGroupMap =
       HashMap<PropertyHandle, std::unique_ptr<PropertySpecificKeyframeGroup>>;
   const KeyframeGroupMap& getPropertySpecificKeyframeGroups() const {
     ensureKeyframeGroups();
     return *m_keyframeGroups;
   }
@@ skipping 24 matching lines @@
       const ComputedStyle* parentStyle) const;
   bool snapshotAllCompositorKeyframes(Element&,
                                       const ComputedStyle& baseStyle,
                                       const ComputedStyle* parentStyle) const;
 
   static KeyframeVector normalizedKeyframesForInspector(
       const KeyframeVector& keyframes) {
     return normalizedKeyframes(keyframes);
   }
 
-  bool affects(PropertyHandle property) const override {
+  bool affects(const PropertyHandle& property) const override {
     ensureKeyframeGroups();
     return m_keyframeGroups->contains(property);
   }
 
   bool isTransformRelatedEffect() const override;
 
  protected:
   KeyframeEffectModelBase(PassRefPtr<TimingFunction> defaultKeyframeEasing)
       : m_lastIteration(0),
         m_lastFraction(std::numeric_limits<double>::quiet_NaN()),
@@ skipping 107 matching lines @@
 
 template <>
 inline bool KeyframeEffectModel<StringKeyframe>::isStringKeyframeEffectModel()
     const {
   return true;
 }
 
 }  // namespace blink
 
 #endif  // KeyframeEffectModel_h