Keep track of fixed positioning in accessibility tree.

content/renderer/accessibility/render_accessibility_impl.cc

 // 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.
 
 #include "content/renderer/accessibility/render_accessibility_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <queue>
@@ skipping 398 matching lines @@
     event_msgs.push_back(event_msg);
 
     // For each node in the update, set the location in our map from
     // ids to locations.
     for (size_t i = 0; i < event_msg.update.nodes.size(); ++i) {
       ui::AXNodeData& src = event_msg.update.nodes[i];
       ui::AXRelativeBounds& dst = locations_[event_msg.update.nodes[i].id];
       dst.offset_container_id = src.offset_container_id;
       dst.bounds = src.location;
       dst.transform.reset(nullptr);
+      dst.is_fixed_positioned = src.is_fixed_positioned;
       if (src.transform)
         dst.transform.reset(new gfx::Transform(*src.transform));
     }
 
     VLOG(1) << "Accessibility event: " << ui::ToString(event.event_type)
             << " on node id " << event_msg.id
             << "\n" << event_msg.update.ToString();
   }
 
   Send(new AccessibilityHostMsg_Events(routing_id(), event_msgs, reset_token_,
@@ skipping 27 matching lines @@
     // be new, so don't continue to explore this branch.
     int id = obj.AxID();
     auto iter = locations_.find(id);
     if (iter == locations_.end())
       continue;
 
     // If the location has changed, append it to the IPC message.
     WebAXObject offset_container;
     WebFloatRect bounds_in_container;
     SkMatrix44 container_transform;
+    bool is_fixed_positioned;
     obj.GetRelativeBounds(offset_container, bounds_in_container,
-                          container_transform);
+                          container_transform, is_fixed_positioned);
     ui::AXRelativeBounds new_location;
     new_location.offset_container_id = offset_container.AxID();
     new_location.bounds = bounds_in_container;
+    new_location.is_fixed_positioned = is_fixed_positioned;
     if (!container_transform.isIdentity())
       new_location.transform = base::WrapUnique(
           new gfx::Transform(container_transform));
     if (iter->second != new_location) {
       AccessibilityHostMsg_LocationChangeParams message;
       message.id = id;
       message.new_location = new_location;
       messages.push_back(message);
     }
 
@@ skipping 237 matching lines @@
 
   const WebDocument& document = GetMainDocument();
   if (document.IsNull())
     return;
 
   WebAXObject::FromWebDocument(document).ScrollToMakeVisibleWithSubFocus(
       WebRect(bounds.x(), bounds.y(), bounds.width(), bounds.height()));
 }
 
 }  // namespace content