It is time.

ui/wm/core/wm_state.cc

-// Copyright (c) 2013 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 "ui/wm/core/wm_state.h"
-
-#include "ui/events/platform/platform_event_source.h"
-#include "ui/wm/core/transient_window_controller.h"
-#include "ui/wm/core/transient_window_stacking_client.h"
-
-namespace wm {
-
-WMState::WMState()
-    : window_stacking_client_(new TransientWindowStackingClient),
-      transient_window_client_(new TransientWindowController) {
-  aura::client::SetWindowStackingClient(window_stacking_client_.get());
-  aura::client::SetTransientWindowClient(transient_window_client_.get());
-}
-
-WMState::~WMState() {
-  if (aura::client::GetWindowStackingClient() == window_stacking_client_.get())
-    aura::client::SetWindowStackingClient(NULL);
-
-  if (aura::client::GetTransientWindowClient() ==
-      transient_window_client_.get()) {
-    aura::client::SetTransientWindowClient(NULL);
-  }
-}
-
-}  // namespace wm