ObserverList::HasObserver now takes a const pointer.

ash/wm/lock_state_controller.h

 // Copyright 2013 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_LOCK_STATE_CONTROLLER_H_
 #define ASH_WM_LOCK_STATE_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/shell_observer.h"
 #include "ash/wm/lock_state_observer.h"
@@ skipping 131 matching lines @@
     DISALLOW_COPY_AND_ASSIGN(TestApi);
   };
 
   LockStateController();
   ~LockStateController() override;
 
   void SetDelegate(scoped_ptr<LockStateControllerDelegate> delegate);
 
   void AddObserver(LockStateObserver* observer);
   void RemoveObserver(LockStateObserver* observer);
-  bool HasObserver(LockStateObserver* observer);
+  bool HasObserver(const LockStateObserver* observer) const;
 
   // Starts locking (with slow animation) that can be cancelled.
   // After locking and |kLockToShutdownTimeoutMs| StartShutdownAnimation()
   // will be called unless CancelShutdownAnimation() is called, if
   // |shutdown_after_lock| is true.
   void StartLockAnimation(bool shutdown_after_lock);
 
   // Starts shutting down (with slow animation) that can be cancelled.
   void StartShutdownAnimation();
 
@@ skipping 163 matching lines @@
   base::Closure lock_screen_displayed_callback_;
 
   base::WeakPtrFactory<LockStateController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LockStateController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_LOCK_STATE_CONTROLLER_H_