Remove OS_CHROMEOS from ui/ash code

chrome/browser/ui/ash/chrome_shell_delegate.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_ASH_CHROME_SHELL_DELEGATE_H_
 #define CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_
 
 #include <memory>
 #include <string>
 
 #include "ash/shell_delegate.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/ash/metrics/chrome_user_metrics_recorder.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
+namespace chromeos {
+class DisplayConfigurationObserver;
+}
+
 namespace keyboard {
 class KeyboardUI;
 }
 
-#if defined(OS_CHROMEOS)
-namespace chromeos {
-class DisplayConfigurationObserver;
-}
-#endif
-
 class ChromeLauncherController;
 
 class ChromeShellDelegate : public ash::ShellDelegate,
                             public content::NotificationObserver {
  public:
   ChromeShellDelegate();
   ~ChromeShellDelegate() override;
 
   // ash::ShellDelegate overrides;
   bool IsFirstRunAfterBoot() const override;
@@ skipping 43 matching lines @@
   content::NotificationRegistrar registrar_;
 
   ChromeLauncherController* shelf_delegate_;
 
   base::ObserverList<ash::VirtualKeyboardStateObserver>
       keyboard_state_observer_list_;
 
   // Proxies events from chrome/browser to ash::UserMetricsRecorder.
   std::unique_ptr<ChromeUserMetricsRecorder> chrome_user_metrics_recorder_;
 
-#if defined(OS_CHROMEOS)
   std::unique_ptr<chromeos::DisplayConfigurationObserver>
       display_configuration_observer_;
-#endif
 
   DISALLOW_COPY_AND_ASSIGN(ChromeShellDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_