cc: Plumbing for storing property trees

cc/trees/property_tree.h

 // 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.
 
 #ifndef CC_TREES_PROPERTY_TREE_H_
 #define CC_TREES_PROPERTY_TREE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 179 matching lines @@
   void UpdateTargetSpaceTransform(TransformNode* node,
                                   TransformNode* target_node);
   void UpdateIsAnimated(TransformNode* node, TransformNode* parent_node);
   void UpdateSnapping(TransformNode* node);
 };
 
 class CC_EXPORT ClipTree final : public PropertyTree<ClipNode> {};
 
 class CC_EXPORT OpacityTree final : public PropertyTree<OpacityNode> {};
 
+class CC_EXPORT PropertyTrees final {
+ public:
+  TransformTree transform_tree;
+  OpacityTree opacity_tree;
+  ClipTree clip_tree;
+};
+
 }  // namespace cc
 
 #endif  // CC_TREES_PROPERTY_TREE_H_