Make InterpolationEnvironment virutal

third_party/WebKit/Source/core/animation/InvalidatableInterpolation.cpp

Index: third_party/WebKit/Source/core/animation/InvalidatableInterpolation.cpp
diff --git a/third_party/WebKit/Source/core/animation/InvalidatableInterpolation.cpp b/third_party/WebKit/Source/core/animation/InvalidatableInterpolation.cpp
index 9a3569e502a152fcc3a62f37f153c4ee9756577f..29a96ef79841ba9676d8f66fab165187a6e57f8b 100644
--- a/third_party/WebKit/Source/core/animation/InvalidatableInterpolation.cpp
+++ b/third_party/WebKit/Source/core/animation/InvalidatableInterpolation.cpp
@@ -4,10 +4,10 @@
 
 #include "core/animation/InvalidatableInterpolation.h"
 
-#include "core/animation/InterpolationEnvironment.h"
+#include <memory>
+#include "core/animation/CSSInterpolationEnvironment.h"
 #include "core/animation/StringKeyframe.h"
 #include "core/css/resolver/StyleResolverState.h"
-#include <memory>
 
 namespace blink {
 
@@ -198,7 +198,9 @@ void InvalidatableInterpolation::SetFlagIfInheritUsed(
     InterpolationEnvironment& environment) const {
   if (!property_.IsCSSProperty() && !property_.IsPresentationAttribute())
     return;
-  if (!environment.GetState().ParentStyle())
+  StyleResolverState& state =
+      ToCSSInterpolationEnvironment(environment).GetState();
+  if (!state.ParentStyle())
     return;
   const CSSValue* start_value =
       ToCSSPropertySpecificKeyframe(*start_keyframe_).Value();
@@ -206,7 +208,7 @@ void InvalidatableInterpolation::SetFlagIfInheritUsed(
       ToCSSPropertySpecificKeyframe(*end_keyframe_).Value();
   if ((start_value && start_value->IsInheritedValue()) ||
       (end_value && end_value->IsInheritedValue())) {
-    environment.GetState().ParentStyle()->SetHasExplicitlyInheritedProperties();
+    state.ParentStyle()->SetHasExplicitlyInheritedProperties();
   }
 }