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..9e6253666959e292129063c489b4e552f41f7c92 100644
--- a/Source/core/animation/Player.cpp
+++ b/Source/core/animation/Player.cpp
@@ -84,13 +84,18 @@ double Player::currentTime() const
     return currentTimeBeforeDrift() - timeDrift();
 }
 
-bool Player::update()
+bool Player::update(double* timeToEffectChange)
 {
-    if (!m_content)
+    if (!m_content) {
+        if (timeToEffectChange)
+            *timeToEffectChange = std::numeric_limits<double>::infinity();
         return false;
+    }
 
     double newTime = isNull(m_timeline->currentTime()) ? nullValue() : currentTime();
     m_content->updateInheritedTime(newTime);
+    if (timeToEffectChange)
+        *timeToEffectChange = m_content->timeToEffectChange();
     return m_content->isCurrent() || m_content->isInEffect();
 }