Add CSSInterpolationType specific ConversionChecker

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

 // Copyright 2015 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 CSSInterpolationType_h
 #define CSSInterpolationType_h
 
 #include "core/animation/InterpolationEnvironment.h"
 #include "core/animation/InterpolationType.h"
 
 namespace blink {
 
 class CSSCustomPropertyDeclaration;
 class PropertyRegistration;
 
 class CSSInterpolationType : public InterpolationType {
  public:
   void SetCustomPropertyRegistration(const PropertyRegistration&);
 
+  class CSSConversionChecker : public ConversionChecker {
+   public:
+    bool IsValid(const InterpolationEnvironment& environment,
+                 const InterpolationValue& underlying) const final {
+      return IsValid(environment.GetState(), underlying);
+    }
+
+   protected:
+    virtual bool IsValid(const StyleResolverState&,
+                         const InterpolationValue& underlying) const = 0;
+  };
+
  protected:
   CSSInterpolationType(PropertyHandle);
 
   CSSPropertyID CssProperty() const { return GetProperty().CssProperty(); }
 
   InterpolationValue MaybeConvertSingle(const PropertySpecificKeyframe&,
                                         const InterpolationEnvironment&,
                                         const InterpolationValue& underlying,
                                         ConversionCheckers&) const final;
   virtual InterpolationValue MaybeConvertNeutral(
@@ skipping 49 matching lines @@
   void ApplyCustomPropertyValue(const InterpolableValue&,
                                 const NonInterpolableValue*,
                                 StyleResolverState&) const;
 
   WeakPersistent<const PropertyRegistration> registration_;
 };
 
 }  // namespace blink
 
 #endif  // CSSInterpolationType_h