CC: Plumb LayerSettings parameter for cc::Layer construction.

cc/trees/layer_tree_settings.h

Index: cc/trees/layer_tree_settings.h
diff --git a/cc/trees/layer_tree_settings.h b/cc/trees/layer_tree_settings.h
index 0e1819b0d9578e0ec7a4e93183d4fa6b2d3b40b0..6c919e2ecb223ecf3d05308f7b92a47a25d7b6f1 100644
--- a/cc/trees/layer_tree_settings.h
+++ b/cc/trees/layer_tree_settings.h
@@ -15,6 +15,14 @@
 
 namespace cc {
 
+class CC_EXPORT LayerSettings {
+ public:
+  LayerSettings();
+  ~LayerSettings();
+
+  bool use_compositor_animation_timelines;
+};
+
 class CC_EXPORT LayerTreeSettings {
  public:
   LayerTreeSettings();
@@ -83,7 +91,7 @@ class CC_EXPORT LayerTreeSettings {
   bool use_cached_picture_in_display_list;
   bool verify_property_trees;
   bool gather_pixel_refs;
-  bool use_compositor_animation_timelines;
+  LayerSettings hud_layer_settings;
 
   LayerTreeDebugState initial_debug_state;