Forward AXPlatformNodeWin calls to the right child.

ui/accessibility/platform/ax_platform_node_win.h

 // Copyright 2015 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 UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
 #define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
 
 #include <atlbase.h>
 #include <atlcom.h>
 #include <oleacc.h>
@@ skipping 284 matching lines @@
   // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType.
   ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type);
 
   // Search forwards (direction == 1) or backwards (direction == -1)
   // from the given offset until the given boundary is found, and
   // return the offset of that boundary.
   LONG FindBoundary(const base::string16& text,
                     IA2TextBoundaryType ia2_boundary,
                     LONG start_offset,
                     ui::TextBoundaryDirection direction);
+
+  // Many MSAA methods take a var_id parameter indicating that the operation
+  // should be performed on a particular child ID, rather than this object.
+  // This method tries to figure out the target object from |var_id| and
+  // returns a pointer to the target object if it exists, otherwise nullptr.
+  // Does not return a new reference.
+  AXPlatformNodeWin* GetTargetFromChildID(const VARIANT& var_id);
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_