Straighten up includes of host_desktop.h/host_desktop_type.h

chrome/browser/ui/aura/active_desktop_monitor.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_UI_AURA_ACTIVE_DESKTOP_MONITOR_H_
 #define CHROME_BROWSER_UI_AURA_ACTIVE_DESKTOP_MONITOR_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "chrome/browser/ui/host_desktop.h"
 #include "ui/aura/env_observer.h"
+#include "ui/gfx/host_desktop_type.h"
 
 // Tracks the most-recently activated host desktop type by observing
 // WindowTreeHost activations.
 class ActiveDesktopMonitor : public aura::EnvObserver {
  public:
   // Constructs an ActiveDesktopMonitor which initially uses |initial_desktop|
   // as the |last_activated_desktop_| until a root window is activated.
   explicit ActiveDesktopMonitor(ui::HostDesktopType initial_desktop);
   ~ActiveDesktopMonitor() override;
 
@@ skipping 11 matching lines @@
   void OnWindowInitialized(aura::Window* window) override;
   void OnHostActivated(aura::WindowTreeHost* host) override;
 
   static ActiveDesktopMonitor* g_instance_;
   ui::HostDesktopType last_activated_desktop_;
 
   DISALLOW_COPY_AND_ASSIGN(ActiveDesktopMonitor);
 };
 
 #endif  // CHROME_BROWSER_UI_AURA_ACTIVE_DESKTOP_MONITOR_H_