Add Scroll Tree data structure

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 <stddef.h>
 
 #include <vector>
 
 #include "cc/base/cc_export.h"
+#include "cc/layers/scroll_blocks_on.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
 namespace proto {
 class ClipNodeData;
 class EffectNodeData;
 class PropertyTree;
 class PropertyTrees;
+class ScrollNodeData;
 class TranformNodeData;
 class TransformTreeData;
 class TreeNode;
 }
 
 // ------------------------------*IMPORTANT*---------------------------------
 // Each class declared here has a corresponding proto defined in
 // cc/proto/property_tree.proto. When making any changes to a class structure
 // including addition/deletion/updation of a field, please also make the
 // change to its proto and the ToProtobuf and FromProtobuf methods for that
@@ skipping 213 matching lines @@
   int clip_id;
 
   bool operator==(const EffectNodeData& other) const;
 
   void ToProtobuf(proto::TreeNode* proto) const;
   void FromProtobuf(const proto::TreeNode& proto);
 };
 
 typedef TreeNode<EffectNodeData> EffectNode;
 
+struct CC_EXPORT ScrollNodeData {
+  ScrollNodeData();
+
+  bool scrollable;
+  bool should_scroll_on_main_thread;
+  ScrollBlocksOn scroll_blocks_on;
+  bool contains_non_fast_scrollable_region;
+
+  int transform_id;
+
+  bool operator==(const ScrollNodeData& other) const;
+
+  void ToProtobuf(proto::TreeNode* proto) const;
+  void FromProtobuf(const proto::TreeNode& proto);
+};
+
+typedef TreeNode<ScrollNodeData> ScrollNode;
+
 template <typename T>
 class CC_EXPORT PropertyTree {
  public:
   PropertyTree();
   virtual ~PropertyTree();
 
   bool operator==(const PropertyTree<T>& other) const;
 
   int Insert(const T& tree_node, int parent_id);
 
@@ skipping 212 matching lines @@
 
   void ClearCopyRequests();
 
   void ToProtobuf(proto::PropertyTree* proto) const;
   void FromProtobuf(const proto::PropertyTree& proto);
 
  private:
   void UpdateOpacities(EffectNode* node, EffectNode* parent_node);
 };
 
+class CC_EXPORT ScrollTree final : public PropertyTree<ScrollNode> {
+ public:
+  bool operator==(const ScrollTree& other) const;
+
+  void ToProtobuf(proto::PropertyTree* proto) const;
+  void FromProtobuf(const proto::PropertyTree& proto);
+};
+
 class CC_EXPORT PropertyTrees final {
  public:
   PropertyTrees();
+  ~PropertyTrees();
 
   bool operator==(const PropertyTrees& other) const;
 
   void ToProtobuf(proto::PropertyTrees* proto) const;
   void FromProtobuf(const proto::PropertyTrees& proto);
 
   TransformTree transform_tree;
   EffectTree effect_tree;
   ClipTree clip_tree;
+  ScrollTree scroll_tree;
   bool needs_rebuild;
   bool non_root_surfaces_enabled;
   int sequence_number;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROPERTY_TREE_H_