Cleanup: Pull some browser keep alive functions into its own file.

chrome/browser/chromeos/login/ui/login_display_host_impl.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_HOST_IMPL_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_HOST_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 15 matching lines @@
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "ui/gfx/display_observer.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/keyboard/keyboard_controller_observer.h"
 #include "ui/views/widget/widget_removals_observer.h"
 #include "ui/wm/public/scoped_drag_drop_disabler.h"
 
 class PrefService;
 
+namespace browser_lifetime {
+class ScopedKeepAlive;
+}
+
 namespace content {
 class RenderFrameHost;
 class WebContents;
 }
 
 namespace chromeos {
 
 class DemoAppLauncher;
 class FocusRingController;
 class KeyboardDrivenOobeKeyHandler;
@@ skipping 253 matching lines @@
   bool startup_sound_played_;
 
   // When true, startup sound should be played only when spoken
   // feedback is enabled.  Otherwise, startup sound should be played
   // in any case.
   bool startup_sound_honors_spoken_feedback_;
 
   // True is subscribed as keyboard controller observer.
   bool is_observing_keyboard_;
 
+  // Keeps the browser alife on the login/oobe screen.
+  scoped_ptr<browser_lifetime::ScopedKeepAlive> keep_alive_;
+
   // Keeps a copy of the old Drag'n'Drop client, so that it would be disabled
   // during a login session and restored afterwards.
   scoped_ptr<aura::client::ScopedDragDropDisabler> scoped_drag_drop_disabler_;
 
   base::WeakPtrFactory<LoginDisplayHostImpl> pointer_factory_;
   base::WeakPtrFactory<LoginDisplayHostImpl> animation_weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LoginDisplayHostImpl);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_HOST_IMPL_H_