It is time.

ui/aura/window_observer.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 "ui/aura/window_observer.h"
-
-#include "base/logging.h"
-#include "ui/aura/window.h"
-
-namespace aura {
-
-WindowObserver::WindowObserver() : observing_(0) {
-}
-
-WindowObserver::~WindowObserver() {
-  // TODO(flackr): Remove this check and observing_ counter when the cause of
-  // http://crbug.com/365364 is discovered.
-  CHECK_EQ(0, observing_);
-}
-
-void WindowObserver::OnObservingWindow(aura::Window* window) {
-  if (!window->HasObserver(this))
-    observing_++;
-}
-
-void WindowObserver::OnUnobservingWindow(aura::Window* window) {
-  if (window->HasObserver(this))
-    observing_--;
-}
-
-}  // namespace aura