ObserverList::HasObserver now takes a const pointer.

chrome/browser/sync/profile_sync_service.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_SYNC_PROFILE_SYNC_SERVICE_H_
 #define CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 271 matching lines @@
   void Initialize();
 
   virtual void SetSyncSetupCompleted();
 
   // ProfileSyncServiceBase implementation.
   bool HasSyncSetupCompleted() const override;
   bool SyncActive() const override;
   syncer::ModelTypeSet GetActiveDataTypes() const override;
   void AddObserver(ProfileSyncServiceBase::Observer* observer) override;
   void RemoveObserver(ProfileSyncServiceBase::Observer* observer) override;
-  bool HasObserver(ProfileSyncServiceBase::Observer* observer) const override;
+  bool HasObserver(
+      const ProfileSyncServiceBase::Observer* observer) const override;
 
   void AddProtocolEventObserver(browser_sync::ProtocolEventObserver* observer);
   void RemoveProtocolEventObserver(
       browser_sync::ProtocolEventObserver* observer);
 
   void AddTypeDebugInfoObserver(syncer::TypeDebugInfoObserver* observer);
   void RemoveTypeDebugInfoObserver(syncer::TypeDebugInfoObserver* observer);
 
   // Add a sync type preference provider. Each provider may only be added once.
   void AddPreferenceProvider(SyncTypePreferenceProvider* provider);
@@ skipping 854 matching lines @@
   BrowsingDataRemover::Observer* browsing_data_remover_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(
     const syncer::SyncProtocolError& error);
 
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_