Include relationship ARIA objects in serialized accessibility tree

ui/accessibility/ax_enums.idl

Index: ui/accessibility/ax_enums.idl
diff --git a/ui/accessibility/ax_enums.idl b/ui/accessibility/ax_enums.idl
index 0f86c3df28c9e99feff506027fd802a02ec95e86..bf116947b89af809080d86082d69c61e1671ea68 100644
--- a/ui/accessibility/ax_enums.idl
+++ b/ui/accessibility/ax_enums.idl
@@ -252,6 +252,7 @@ namespace ui {
 
     // Relationships between this element and other elements.
     ax_attr_title_ui_element,
+    ax_attr_activedescendant_id,
 
     // Color value for AX_ROLE_COLOR_WELL, each component is 0..255
     ax_attr_color_value_red,
@@ -306,6 +307,13 @@ namespace ui {
     // column.
     ax_attr_indirect_child_ids,
 
+    // Relationships between this element and other elements.
+    ax_attr_controls_ids,
+    ax_attr_describedby_ids,
+    ax_attr_flowto_ids,
+    ax_attr_labelledby_ids,
+    ax_attr_owns_ids,
+
     // Character indices where line breaks occur.
     ax_attr_line_breaks,