Introduce KeyframeEffectReadOnly interface

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

Index: third_party/WebKit/Source/core/animation/SampledEffect.h
diff --git a/third_party/WebKit/Source/core/animation/SampledEffect.h b/third_party/WebKit/Source/core/animation/SampledEffect.h
index bf31c07da552bbf11341c3cba640ca14f8b2fd94..617b9dcfa543f73fe84004ab0a6abb88383ec753 100644
--- a/third_party/WebKit/Source/core/animation/SampledEffect.h
+++ b/third_party/WebKit/Source/core/animation/SampledEffect.h
@@ -8,6 +8,7 @@
 #include "core/animation/Animation.h"
 #include "core/animation/Interpolation.h"
 #include "core/animation/KeyframeEffect.h"
+#include "core/animation/KeyframeEffectReadOnly.h"
 #include "wtf/Allocator.h"
 #include "wtf/Vector.h"
 
@@ -31,7 +32,7 @@ public:
 
     KeyframeEffect* effect() const { return m_effect; }
     unsigned sequenceNumber() const { return m_sequenceNumber; }
-    KeyframeEffect::Priority priority() const { return m_priority; }
+    KeyframeEffectReadOnly::Priority priority() const { return m_priority; }
     bool willNeverChange() const;
     void removeReplacedInterpolations(const HashSet<PropertyHandle>&);
     void updateReplacedProperties(HashSet<PropertyHandle>&);
@@ -44,7 +45,7 @@ private:
     WeakMember<KeyframeEffect> m_effect;
     Vector<RefPtr<Interpolation>> m_interpolations;
     const unsigned m_sequenceNumber;
-    KeyframeEffect::Priority m_priority;
+    KeyframeEffectReadOnly::Priority m_priority;
 };
 
 } // namespace blink