CC Animations: Fix the case when main-thread player changes layer_id.

cc/animation/animation_player.cc

Index: cc/animation/animation_player.cc
diff --git a/cc/animation/animation_player.cc b/cc/animation/animation_player.cc
index c237aa7fb8b17f5f7172f29d57d23a54ecdcb517..dee19eabdd1e97f9292b55be16af959c8c296acd 100644
--- a/cc/animation/animation_player.cc
+++ b/cc/animation/animation_player.cc
@@ -154,15 +154,12 @@ void AnimationPlayer::RemoveAnimation(int animation_id) {
 }
 
 void AnimationPlayer::PushPropertiesTo(AnimationPlayer* player_impl) {
-  if (!element_animations_) {
-    if (player_impl->element_animations())
+  if (layer_id_ != player_impl->layer_id()) {
+    if (player_impl->layer_id())
       player_impl->DetachLayer();
-    return;
+    if (layer_id_)
+      player_impl->AttachLayer(layer_id_);
   }
-
-  DCHECK(layer_id_);
-  if (!player_impl->element_animations())
-    player_impl->AttachLayer(layer_id_);
 }
 
 void AnimationPlayer::NotifyAnimationStarted(