text: // 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() {
    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_--;
  }
  
  void WindowObserver::OnEmbeddedAppDisconnected(Window* window) {}
  
  }  // namespace aura
  