Implemented IAccessible2 reverse relations.

ui/accessibility/ax_tree_combiner.cc

 // Copyright 2016 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.
 
 #include "ui/accessibility/ax_tree.h"
 #include "ui/accessibility/ax_tree_combiner.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 namespace ui {
 namespace {
 
 // Return true if |attr| is a node ID that would need to be mapped when
 // renumbering the ids in a combined tree.
 bool IsNodeIdIntAttribute(AXIntAttribute attr) {
   switch (attr) {
     case AX_ATTR_ACTIVEDESCENDANT_ID:
+    case AX_ATTR_MEMBER_OF_ID:
     case AX_ATTR_NEXT_ON_LINE_ID:
     case AX_ATTR_PREVIOUS_ON_LINE_ID:
     case AX_ATTR_TABLE_HEADER_ID:
     case AX_ATTR_TABLE_COLUMN_HEADER_ID:
     case AX_ATTR_TABLE_ROW_HEADER_ID:
       return true;
 
     // Note: all of the attributes are included here explicitly,
     // rather than using "default:", so that it's a compiler error to
     // add a new attribute without explicitly considering whether it's
@@ skipping 206 matching lines @@
     // Recurse into the child tree now, if any.
     if (child_tree)
       ProcessTree(child_tree);
   }
 
   // Reset the transform.
   transform_ = old_transform;
 }
 
 }  // namespace ui