cc: Remove support for disabling non-root render surfaces.

cc/trees/property_tree.h

Index: cc/trees/property_tree.h
diff --git a/cc/trees/property_tree.h b/cc/trees/property_tree.h
index 34abaa9275daa5f66b53b18d803575a4b1d99828..601cbaf2f74d77f52e744ff0a075d93fd59b904c 100644
--- a/cc/trees/property_tree.h
+++ b/cc/trees/property_tree.h
@@ -394,8 +394,7 @@ class CC_EXPORT EffectTree final : public PropertyTree<EffectNode> {
     return render_surfaces_[id].get();
   }
 
-  void UpdateRenderSurfaces(LayerTreeImpl* layer_tree_impl,
-                            bool non_root_surfaces_enabled);
+  void UpdateRenderSurfaces(LayerTreeImpl* layer_tree_impl);
 
   bool ContributesToDrawnSurface(int id);
 
@@ -654,7 +653,6 @@ class CC_EXPORT PropertyTrees final {
   ClipTree clip_tree;
   ScrollTree scroll_tree;
   bool needs_rebuild;
-  bool non_root_surfaces_enabled;
   bool can_adjust_raster_scales;
   // Change tracking done on property trees needs to be preserved across commits
   // (when they are not rebuild). We cache a global bool which stores whether