Add a window property to associate RWHVA with its child AX tree ID

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index 4d368eb27b6e1c9e7a45b7b8c48b744624f1f5e0..0a5450f62c1e6535ee7102e1738f07fa8306e748 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -1968,6 +1968,9 @@ void RenderFrameHostImpl::OnAccessibilityEvents(
 
   RenderWidgetHostViewBase* view = GetViewForAccessibility();
 
+  if (frame_tree_node_->IsMainFrame() && view)
+    view->UpdateAXTreeID(GetAXTreeID());
+
   AccessibilityMode accessibility_mode = delegate_->GetAccessibilityMode();
   if ((accessibility_mode != AccessibilityModeOff) && view && is_active()) {
     if (accessibility_mode & ACCESSIBILITY_MODE_FLAG_NATIVE_APIS)