Views a11y: Use AX_ROLE_POP_UP_BUTTON for views::Combobox.

ui/views/controls/combobox/combobox.cc

Index: ui/views/controls/combobox/combobox.cc
diff --git a/ui/views/controls/combobox/combobox.cc b/ui/views/controls/combobox/combobox.cc
index c948d755e62f839487c7238641e7cb9c17e87a30..615318fe42c1d7e1a549b7f3fbd8387b5a41eb3f 100644
--- a/ui/views/controls/combobox/combobox.cc
+++ b/ui/views/controls/combobox/combobox.cc
@@ -751,7 +751,11 @@ void Combobox::OnBlur() {
 }
 
 void Combobox::GetAccessibleNodeData(ui::AXNodeData* node_data) {
-  node_data->role = ui::AX_ROLE_COMBO_BOX;
+  // AX_ROLE_COMBO_BOX is for UI elements with a dropdown and an editable text
+  // field, which views::Combobox does not have. Use AX_ROLE_POP_UP_BUTTON to
+  // match an HTML <select> element.
+  node_data->role = ui::AX_ROLE_POP_UP_BUTTON;
+
   node_data->SetName(accessible_name_);
   node_data->SetValue(model_->GetItemAt(selected_index_));
   if (enabled()) {