CC Animations: Make LayerAnimationController creation optional

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index acda8a70f33dea4c697f4dadd93a8e3e830c7042..b552de758dcaf952ef16fb87ce71e7f3b0228f35 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -32,7 +32,9 @@
 #include "cc/base/switches.h"
 #include "cc/blink/web_external_bitmap_impl.h"
 #include "cc/blink/web_layer_impl.h"
+#include "cc/layers/layer.h"
 #include "cc/resources/tile_task_worker_pool.h"
+#include "cc/trees/layer_tree_settings.h"
 #include "components/scheduler/renderer/renderer_scheduler.h"
 #include "content/child/appcache/appcache_dispatcher.h"
 #include "content/child/appcache/appcache_frontend_impl.h"
@@ -574,6 +576,11 @@ void RenderThreadImpl::Init() {
   cc_blink::WebLayerImpl::SetImplSidePaintingEnabled(
       is_impl_side_painting_enabled_);
 
+  cc::LayerSettings layer_settings;
+  if (command_line.HasSwitch(switches::kEnableCompositorAnimationTimelines))
+    layer_settings.use_compositor_animation_timelines = true;
+  cc_blink::WebLayerImpl::SetLayerSettings(layer_settings);
+
   is_zero_copy_enabled_ = command_line.HasSwitch(switches::kEnableZeroCopy);
   is_one_copy_enabled_ = !command_line.HasSwitch(switches::kDisableOneCopy);