cc: LayerTreeHostImpl uses element id to tick animations

cc/layers/scrollbar_layer_unittest.cc

Index: cc/layers/scrollbar_layer_unittest.cc
diff --git a/cc/layers/scrollbar_layer_unittest.cc b/cc/layers/scrollbar_layer_unittest.cc
index 8824b2880d9ecb1b055a02837cfc7a247432d1a2..d8240c67f02f08dc61e613b44b368083cbd173d7 100644
--- a/cc/layers/scrollbar_layer_unittest.cc
+++ b/cc/layers/scrollbar_layer_unittest.cc
@@ -628,10 +628,10 @@ TEST_F(ScrollbarLayerTest, ScrollbarLayerOpacity) {
   EXPECT_EQ(node->opacity, 0.f);
 
   // This tests that activation does not change the opacity of scrollbar layer.
-  LayerImpl* scrollbar_layer_impl =
-      layer_tree_impl->LayerById(scrollbar_layer->id());
-  layer_tree_impl->property_trees()->effect_tree.OnOpacityAnimated(
-      0.25f, scrollbar_layer_impl->effect_tree_index(), layer_tree_impl);
+  ScrollbarLayerImplBase* scrollbar_layer_impl =
+      static_cast<ScrollbarLayerImplBase*>(
+          layer_tree_impl->LayerById(scrollbar_layer->id()));
+  scrollbar_layer_impl->SetOverlayScrollbarLayerOpacityAnimated(0.25f);
   host_impl->CreatePendingTree();
   layer_impl_tree_root = layer_tree_host_->CommitAndCreatePendingTree();
   layer_tree_impl = layer_impl_tree_root->layer_tree_impl();