cc: Put to_target and to_screen behind an accessor.

cc/trees/property_tree.h

Index: cc/trees/property_tree.h
diff --git a/cc/trees/property_tree.h b/cc/trees/property_tree.h
index 4264a1c6962fb911ae170753e3f01bf2751dce09..8d8b3726a618b838bcb12dc37d648e555e082848 100644
--- a/cc/trees/property_tree.h
+++ b/cc/trees/property_tree.h
@@ -505,6 +505,15 @@ class CC_EXPORT TransformTree final : public PropertyTree<TransformNode> {
     return nodes_affected_by_outer_viewport_bounds_delta_;
   }
 
+  gfx::Transform ToTarget(int id) const;

[ajuma, 2016/06/03 19:35:29]

const gfx::Transform&

+  void SetToTarget(int id, const gfx::Transform& transform);
+  gfx::Transform ToScreen(int id) const;

[ajuma, 2016/06/03 19:35:29]

const gfx::Transform&

+  void SetToScreen(int id, const gfx::Transform& transform);
+  int TargetId(int id) const;

[ajuma, 2016/06/03 19:35:29]

Nit: here and below, s/id/node_id (so it's clearer we mean the node id and not
the target id).

+  void SetTargetId(int id, int target_id);
+  int ContentTargetId(int id) const;
+  void SetContentTargetId(int id, int content_target_id);
+
   gfx::Transform ToScreenSpaceTransformWithoutSublayerScale(int id) const;
 
   void ToProtobuf(proto::PropertyTree* proto) const;