aura: Remove layerless windows.

chrome/browser/ui/aura/accessibility/ax_root_obj_wrapper.cc

 // Copyright 2014 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 "chrome/browser/ui/aura/accessibility/ax_root_obj_wrapper.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/aura/window.h"
 #include "ui/views/accessibility/ax_aura_obj_cache.h"
 #include "ui/views/accessibility/ax_window_obj_wrapper.h"
 
 AXRootObjWrapper::AXRootObjWrapper(int32 id)
     : id_(id), alert_window_(new aura::Window(NULL)) {
+  alert_window_->Init(ui::LAYER_NOT_DRAWN);
 }
 
 AXRootObjWrapper::~AXRootObjWrapper() {
   if (alert_window_) {
     delete alert_window_;
     alert_window_ = NULL;
   }
 }
 
 views::AXAuraObjWrapper* AXRootObjWrapper::GetAlertForText(
@@ skipping 24 matching lines @@
 void AXRootObjWrapper::Serialize(ui::AXNodeData* out_node_data) {
   out_node_data->id = id_;
   out_node_data->role = ui::AX_ROLE_DESKTOP;
   // TODO(dtseng): Apply a richer set of states.
   out_node_data->state = 0;
 }
 
 int32 AXRootObjWrapper::GetID() {
   return id_;
 }