Implement CSS: scroll-boundary-behavior

cc/trees/property_tree_builder.cc

Index: cc/trees/property_tree_builder.cc
diff --git a/cc/trees/property_tree_builder.cc b/cc/trees/property_tree_builder.cc
index af37d721e334dd2bfbb88940680aef33c360af56..48c194688dacc72e66e9052b5a35538de77a139e 100644
--- a/cc/trees/property_tree_builder.cc
+++ b/cc/trees/property_tree_builder.cc
@@ -1050,6 +1050,7 @@ void AddScrollNodeIfNeeded(
     node.element_id = layer->element_id();
     node.transform_id =
         data_for_children->transform_tree_parent->transform_tree_index();
+    node.scroll_boundary_behavior = layer->scroll_boundary_behavior();

[ajuma, 2017/06/30 20:46:49]

After removing scroll_boundary_behavior from LayerImpl, this will need to be
changed to use a helper function (e.g. like we have for
UserScrollableHorizontal).

[sunyunjia, 2017/07/14 02:59:00]

Done.

 
     node_id =
         data_for_children->property_trees->scroll_tree.Insert(node, parent_id);