Update cc effect node documentation.

cc/trees/property_tree.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 
 #include <set>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 806 matching lines @@
   if (parent_node && parent_node->effect_changed) {
     node->effect_changed = true;
   }
 }
 
 void EffectTree::UpdateBackfaceVisibility(EffectNode* node,
                                           EffectNode* parent_node) {
   if (parent_node && parent_node->hidden_by_backface_visibility) {
     node->hidden_by_backface_visibility = true;
     return;
-  } else if (node->double_sided) {
+  }
+  if (node->double_sided) {
     node->hidden_by_backface_visibility = false;
     return;
   }
   node->hidden_by_backface_visibility =
       property_trees()
           ->transform_tree.cached_data()[node->transform_id]
           .is_showing_backface;
 }
 
 void EffectTree::UpdateSurfaceContentsScale(EffectNode* effect_node) {
@@ skipping 1262 matching lines @@
   const EffectNode* effect_node = effect_tree.Node(effect_id);
 
   if (effect_node->surface_contents_scale.x() != 0.0 &&
       effect_node->surface_contents_scale.y() != 0.0)
     screen_space_transform.Scale(1.0 / effect_node->surface_contents_scale.x(),
                                  1.0 / effect_node->surface_contents_scale.y());
   return screen_space_transform;
 }
 
 }  // namespace cc