Plumb timeToNextEffect through players and animation

Source/core/animation/TimedItem.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 56 matching lines @@
         virtual ~EventDelegate() { };
         virtual void onEventCondition(const TimedItem*, bool isFirstSample, Phase previousPhase, double previousIteration) = 0;
     };
 
     virtual ~TimedItem() { }
 
     Phase phase() const { return ensureCalculated().phase; }
     bool isCurrent() const { return ensureCalculated().isCurrent; }
     bool isInEffect() const { return ensureCalculated().isInEffect; }
     bool isInPlay() const { return ensureCalculated().isInPlay; }
+    double timeToEffectChange() const { return ensureCalculated().timeToEffectChange; }
 
     double startTime() const { return m_startTime; }
 
     double currentIteration() const { return ensureCalculated().currentIteration; }
     double activeDuration() const { return ensureCalculated().activeDuration; }
     double timeFraction() const { return ensureCalculated().timeFraction; }
     const Player* player() const { return m_player; }
 
     const Timing& specified() const { return m_specified; }
 
 protected:
     TimedItem(const Timing&, PassOwnPtr<EventDelegate> = nullptr);
 
     // When TimedItem receives a new inherited time via updateInheritedTime
     // it will (if necessary) recalculate timings and (if necessary) call
     // updateChildrenAndEffects.
     void updateInheritedTime(double inheritedTime) const;
+
+private:
     virtual void updateChildrenAndEffects(bool wasInEffect) const = 0;
     virtual double intrinsicIterationDuration() const { return 0; };
     virtual void willDetach() = 0;
+    virtual double calculateTimeToEffectChange(double inheritedTime, double activeTime, Phase) const = 0;
 
-private:
     void attach(Player* player) { m_player = player; };
     void detach()
     {
         ASSERT(m_player);
         willDetach();
         m_player = 0;
     };
 
     // FIXME: m_parent and m_startTime are placeholders, they depend on timing groups.
     TimedItem* const m_parent;
     const double m_startTime;
     Player* m_player;
     Timing m_specified;
     OwnPtr<EventDelegate> m_eventDelegate;
 
     // FIXME: Should be versioned by monotonic value on player.
     mutable struct CalculatedTiming {
         double activeDuration;
         Phase phase;
         double currentIteration;
         double timeFraction;
         bool isCurrent;
         bool isInEffect;
         bool isInPlay;
+        double timeToEffectChange;
     } m_calculated;
     mutable bool m_isFirstSample;
 
     // FIXME: Should check the version and reinherit time if inconsistent.
     const CalculatedTiming& ensureCalculated() const { return m_calculated; }
 };
 
 } // namespace WebCore
 
 #endif