Make InterpolationEnvironment virutal

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/CSSInterpolationEnvironment.h"
 #include "core/animation/InterpolationType.h"
 
 namespace blink {
 
 class CSSCustomPropertyDeclaration;
+class ComputedStyle;
 class PropertyRegistration;
+class StyleResolverState;
 
 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);
+      return IsValid(ToCSSInterpolationEnvironment(environment).GetState(),
+                     underlying);
     }
 
    protected:
     virtual bool IsValid(const StyleResolverState&,
                          const InterpolationValue& underlying) const = 0;
   };
 
  protected:
   CSSInterpolationType(PropertyHandle);
 
@@ skipping 56 matching lines @@
   void ApplyCustomPropertyValue(const InterpolableValue&,
                                 const NonInterpolableValue*,
                                 StyleResolverState&) const;
 
   WeakPersistent<const PropertyRegistration> registration_;
 };
 
 }  // namespace blink
 
 #endif  // CSSInterpolationType_h