CC Animations: Make LayerAnimationController creation optional

content/test/web_layer_tree_view_impl_for_testing.cc

Index: content/test/web_layer_tree_view_impl_for_testing.cc
diff --git a/content/test/web_layer_tree_view_impl_for_testing.cc b/content/test/web_layer_tree_view_impl_for_testing.cc
index 6d4122056f7a9415d2bb9e90112978c98ce7be9b..3bedfe028b2b5b81bff3c1aadef327b1035019b0 100644
--- a/content/test/web_layer_tree_view_impl_for_testing.cc
+++ b/content/test/web_layer_tree_view_impl_for_testing.cc
@@ -162,6 +162,12 @@ void WebLayerTreeViewImplForTesting::DidFailToInitializeOutputSurface() {
   RequestNewOutputSurface();
 }
 
+void WebLayerTreeViewImplForTesting::registerForAnimations(
+    blink::WebLayer* layer) {
+  cc::Layer* cc_layer = static_cast<cc_blink::WebLayerImpl*>(layer)->layer();
+  cc_layer->RegisterForAnimations(layer_tree_host_->animation_registrar());
+}
+
 void WebLayerTreeViewImplForTesting::registerViewportLayers(
     const blink::WebLayer* overscrollElasticityLayer,
     const blink::WebLayer* pageScaleLayer,