Allow animations with inactive observers to reach the Starting state

cc/animation/layer_animation_controller.cc

Index: cc/animation/layer_animation_controller.cc
diff --git a/cc/animation/layer_animation_controller.cc b/cc/animation/layer_animation_controller.cc
index 5e20dd5d6ee287e45b4264a34958e931d0478ecd..ce733223a12f1d0af4c82c713c819488ee9da09f 100644
--- a/cc/animation/layer_animation_controller.cc
+++ b/cc/animation/layer_animation_controller.cc
@@ -142,7 +142,7 @@ void LayerAnimationController::TransferAnimationsTo(
 }
 
 void LayerAnimationController::Animate(double monotonic_time) {
-  if (!HasActiveValueObserver())
+  if (!HasValueObserver())
     return;
 
   StartAnimationsWaitingForNextTick(monotonic_time);
@@ -716,6 +716,15 @@ void LayerAnimationController::NotifyObserversTransformAnimated(
                     OnTransformAnimated(transform));
 }
 
+bool LayerAnimationController::HasValueObserver() {
+  if (value_observers_.might_have_observers()) {
+    ObserverListBase<LayerAnimationValueObserver>::Iterator it(
+        value_observers_);
+    return it.GetNext() != NULL;
+  }
+  return false;
+}
+
 bool LayerAnimationController::HasActiveValueObserver() {
   if (value_observers_.might_have_observers()) {
     ObserverListBase<LayerAnimationValueObserver>::Iterator it(