Plumb timeToNextEffect through players and animation

Source/core/animation/Player.cpp

Index: Source/core/animation/Player.cpp
diff --git a/Source/core/animation/Player.cpp b/Source/core/animation/Player.cpp
index 0d44da78a694dae2ce567327b17c3158d961fe7b..23e1b5edc939e30294d4c26e364b61a514b7f5ec 100644
--- a/Source/core/animation/Player.cpp
+++ b/Source/core/animation/Player.cpp
@@ -84,13 +84,14 @@ double Player::currentTime() const
     return currentTimeBeforeDrift() - timeDrift();
 }
 
-bool Player::update()
+bool Player::update(double& timeToEffectChange)
 {
     if (!m_content)
         return false;
 
     double newTime = isNull(m_timeline->currentTime()) ? nullValue() : currentTime();
     m_content->updateInheritedTime(newTime);
+    timeToEffectChange = m_content->timeToEffectChange();
     return m_content->isCurrent() || m_content->isInEffect();
 }