Keep track of fixed positioning in accessibility tree.

content/common/accessibility_messages.h

 // Copyright (c) 2012 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.
 
 // IPC messages for accessibility.
 // Multiply-included message file, hence no include guard.
 
 #include "content/common/ax_content_node_data.h"
 #include "content/common/content_export.h"
 #include "content/common/view_message_enums.h"
@@ skipping 40 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(transform)
   IPC_STRUCT_TRAITS_MEMBER(string_attributes)
   IPC_STRUCT_TRAITS_MEMBER(int_attributes)
   IPC_STRUCT_TRAITS_MEMBER(float_attributes)
   IPC_STRUCT_TRAITS_MEMBER(bool_attributes)
   IPC_STRUCT_TRAITS_MEMBER(intlist_attributes)
   IPC_STRUCT_TRAITS_MEMBER(html_attributes)
   IPC_STRUCT_TRAITS_MEMBER(child_ids)
   IPC_STRUCT_TRAITS_MEMBER(content_int_attributes)
   IPC_STRUCT_TRAITS_MEMBER(offset_container_id)
+  IPC_STRUCT_TRAITS_MEMBER(is_fixed_positioned)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(content::AXContentTreeData)
   IPC_STRUCT_TRAITS_MEMBER(tree_id)
   IPC_STRUCT_TRAITS_MEMBER(parent_tree_id)
   IPC_STRUCT_TRAITS_MEMBER(focused_tree_id)
   IPC_STRUCT_TRAITS_MEMBER(url)
   IPC_STRUCT_TRAITS_MEMBER(title)
   IPC_STRUCT_TRAITS_MEMBER(mimetype)
   IPC_STRUCT_TRAITS_MEMBER(doctype)
@@ skipping 141 matching lines @@
                     gfx::Point /* location tested */,
                     int /* node id of result */,
                     ui::AXEvent /* event to fire */)
 
 // Sent in response to AccessibilityMsg_SnapshotTree. The callback id that was
 // passed to the request will be returned in |callback_id|, along with
 // a standalone snapshot of the accessibility tree.
 IPC_MESSAGE_ROUTED2(AccessibilityHostMsg_SnapshotResponse,
                     int /* callback_id */,
                     content::AXContentTreeUpdate)