Enumerate the return value of dispatchEvent so it is clear.

third_party/WebKit/Source/core/animation/Animation.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 159 matching lines @@
     int compositorGroup() const { return m_compositorGroup; }
 
     static bool hasLowerPriority(const Animation* animation1, const Animation* animation2)
     {
         return animation1->sequenceNumber() < animation2->sequenceNumber();
     }
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
-    bool dispatchEventInternal(PassRefPtrWillBeRawPtr<Event>) override;
+    EventTarget::DispatchEventResult dispatchEventInternal(PassRefPtrWillBeRawPtr<Event>) override;
     bool addEventListenerInternal(const AtomicString& eventType, PassRefPtrWillBeRawPtr<EventListener>, const EventListenerOptions&) override;
 
 private:
     Animation(ExecutionContext*, AnimationTimeline&, AnimationEffect*);
 
     void clearOutdated();
 
     double effectEnd() const;
     bool limited(double currentTime) const;
 
@@ skipping 103 matching lines @@
 
     OwnPtr<CompositorAnimationPlayer> m_compositorPlayer;
 
     bool m_currentTimePending;
     bool m_stateIsBeingUpdated;
 };
 
 } // namespace blink
 
 #endif // Animation_h