Highlighting on UAOS - alternate approach

cc/layers/layer.h

 // Copyright 2010 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.
 
 #ifndef CC_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 172 matching lines @@
   bool transform_is_invertible() const { return transform_is_invertible_; }
 
   void SetScrollParent(Layer* parent);
 
   Layer* scroll_parent() { return scroll_parent_; }
   const Layer* scroll_parent() const { return scroll_parent_; }
 
   void AddScrollChild(Layer* child);
   void RemoveScrollChild(Layer* child);
 
+  bool has_scroll_children() const {
+    return scroll_children_ && !scroll_children_->empty();
+  }
+
   std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
   const std::set<Layer*>* scroll_children() const {
     return scroll_children_.get();
   }
 
   void SetClipParent(Layer* ancestor);
 
   Layer* clip_parent() { return clip_parent_; }
   const Layer* clip_parent() const {
     return clip_parent_;
@@ skipping 423 matching lines @@
   DrawProperties<Layer> draw_properties_;
 
   PaintProperties paint_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_