Plumb timeToNextEffect through players and animation

Source/core/animation/Animation.cpp

Index: Source/core/animation/Animation.cpp
diff --git a/Source/core/animation/Animation.cpp b/Source/core/animation/Animation.cpp
index d48b39a4f93c5485996b26583786688c2f833723..e427c631e6d9517d7a785c31a86894c09f46e7c0 100644
--- a/Source/core/animation/Animation.cpp
+++ b/Source/core/animation/Animation.cpp
@@ -91,4 +91,22 @@ void Animation::updateChildrenAndEffects(bool wasInEffect) const
         const_cast<Animation*>(this)->clearEffects();
 }
 
+double Animation::calculateTimeToEffectChange(double inheritedTime, double activeTime, Phase phase) const
+{
+    if (phase == PhaseBefore) {
+        return activeTime - inheritedTime;
+    }
+    if (phase == PhaseActive) {
+        return 0;
+    }
+    if (phase == PhaseAfter) {
+        // If this Animation is still in effect then it will need to update
+        // when its parent goes out of effect. We have no way of knowing when
+        // that will be, however, so the parent will need to supply it.
+        return -1;
+    }
+    ASSERT_NOT_REACHED();
+    return 0;
+}
+
 } // namespace WebCore