Add lock pod animation on unlock.

ash/wm/session_state_controller.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 ASH_WM_SESSION_STATE_CONTROLLER_H_
 #define ASH_WM_SESSION_STATE_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/shell_observer.h"
 #include "ash/wm/session_state_animator.h"
@@ skipping 113 matching lines @@
 
   // Cancels shutting down and reverts shutdown animation.
   virtual void CancelShutdownAnimation() = 0;
 
   // Called when Chrome gets a request to display the lock screen.
   virtual void OnStartingLock() = 0;
 
   // Displays the shutdown animation and requests shutdown when it's done.
   virtual void RequestShutdown() = 0;
 
+  // Called when ScreenLocker is ready to close, but not yet destroyed.
+  // Can be used to display "hiding" animations on unlock.
+  // |callback| will be called when all animations are done.
+  virtual void OnLockScreenHide(base::Callback<void(void)>& callback) = 0;
+
  protected:
   friend class test::PowerButtonControllerTest;
 
   bool IsLoggedInAsNonGuest() const;
 
   scoped_ptr<internal::SessionStateAnimator> animator_;
 
   scoped_ptr<SessionStateControllerDelegate> delegate_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SessionStateController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_SESSION_STATE_CONTROLLER_H_