cc : Use effect node data to determine which opacity wins at commit.

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index 02492e54b8e8e7e06b44103b0847e2179b5c58ba..019f62048dd03b09c5ce7272c743e6b8ab2aa359 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -721,9 +721,6 @@ void LayerImpl::UpdatePropertyTreeForScrollingAndAnimationIfNeeded() {
   if (scrollable())
     UpdatePropertyTreeScrollOffset();
 
-  if (HasAnyAnimationTargetingProperty(TargetProperty::OPACITY))
-    UpdatePropertyTreeOpacity();
-
   if (HasAnyAnimationTargetingProperty(TargetProperty::TRANSFORM)) {
     UpdatePropertyTreeTransform();
     UpdatePropertyTreeTransformIsAnimated(
@@ -754,6 +751,7 @@ void LayerImpl::OnOpacityAnimated(float opacity) {
   UpdatePropertyTreeOpacity();
   SetNeedsPushProperties();
   layer_tree_impl()->set_needs_update_draw_properties();
+  layer_tree_impl()->AddToOpacityAnimationsMap(id(), opacity);
 }
 
 void LayerImpl::OnTransformAnimated(const gfx::Transform& transform) {
@@ -799,8 +797,6 @@ void LayerImpl::OnOpacityIsPotentiallyAnimatingChanged(
   DCHECK(layer_tree_impl_);
   EffectTree& effect_tree = layer_tree_impl_->property_trees()->effect_tree;
   EffectNode* node = effect_tree.Node(effect_tree_index());
-  if (!node)
-    return;
   if (node->owner_id == id()) {
     node->data.has_potential_opacity_animation = has_potential_animation;
     effect_tree.set_needs_update(true);