ObserverList::HasObserver now takes a const pointer.

chromeos/dbus/update_engine_client.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 CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_
 #define CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 57 matching lines @@
     // Called when the status is updated.
     virtual void UpdateStatusChanged(const Status& status) {}
   };
 
   virtual ~UpdateEngineClient();
 
   // Adds and removes the observer.
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
   // Returns true if this object has the given observer.
-  virtual bool HasObserver(Observer* observer) = 0;
+  virtual bool HasObserver(const Observer* observer) const = 0;
 
   // Called once RequestUpdateCheck() is complete. Takes one parameter:
   // - UpdateCheckResult: the result of the update check.
   typedef base::Callback<void(UpdateCheckResult)> UpdateCheckCallback;
 
   // Requests an update check and calls |callback| when completed.
   virtual void RequestUpdateCheck(const UpdateCheckCallback& callback) = 0;
 
   // Reboots if update has been performed.
   virtual void RebootAfterUpdate() = 0;
@@ skipping 55 matching lines @@
   // Create() should be used instead.
   UpdateEngineClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(UpdateEngineClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_