cc: Stop creating unused 0 property tree nodes other than transform

cc/layers/render_surface_impl.cc

Index: cc/layers/render_surface_impl.cc
diff --git a/cc/layers/render_surface_impl.cc b/cc/layers/render_surface_impl.cc
index a2d128ca1f0d480810720c2d85c48c7bed3fec72..3c38bec60ea659038b7bd9bc63774045bcc49278 100644
--- a/cc/layers/render_surface_impl.cc
+++ b/cc/layers/render_surface_impl.cc
@@ -47,10 +47,7 @@ RenderSurfaceImpl* RenderSurfaceImpl::render_target() {
       owning_layer_->layer_tree_impl()->property_trees()->effect_tree;
   EffectNode* node = effect_tree.Node(EffectTreeIndex());
   EffectNode* target_node = effect_tree.Node(node->target_id);
-  if (target_node->id != 0)
-    return target_node->render_surface;
-  else
-    return this;
+  return target_node->render_surface;
 }
 
 const RenderSurfaceImpl* RenderSurfaceImpl::render_target() const {
@@ -58,10 +55,7 @@ const RenderSurfaceImpl* RenderSurfaceImpl::render_target() const {
       owning_layer_->layer_tree_impl()->property_trees()->effect_tree;
   const EffectNode* node = effect_tree.Node(EffectTreeIndex());
   const EffectNode* target_node = effect_tree.Node(node->target_id);
-  if (target_node->id != 0)
-    return target_node->render_surface;
-  else
-    return this;
+  return target_node->render_surface;
 }
 
 RenderSurfaceImpl::DrawProperties::DrawProperties() {