Replace more ObserverList with base::ObserverList.

sync/internal_api/sync_encryption_handler_impl.h

 // Copyright 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 SYNC_INTERNAL_API_SYNC_ENCRYPTION_HANDLER_IMPL_H_
 #define SYNC_INTERNAL_API_SYNC_ENCRYPTION_HANDLER_IMPL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 245 matching lines @@
   // Helper to enable encrypt everything, notifying observers if necessary.
   // Will not perform re-encryption.
   void EnableEncryptEverythingImpl(syncable::BaseTransaction* const trans);
 
   // If an explicit passphrase is in use, returns the time at which it was set
   // (if known). Else return base::Time().
   base::Time GetExplicitPassphraseTime() const;
 
   base::ThreadChecker thread_checker_;
 
-  ObserverList<SyncEncryptionHandler::Observer> observers_;
+  base::ObserverList<SyncEncryptionHandler::Observer> observers_;
 
   // The current user share (for creating transactions).
   UserShare* user_share_;
 
   // Container for all data that can be accessed from multiple threads. Do not
   // access this object directly. Instead access it via UnlockVault(..) and
   // UnlockVaultMutable(..).
   Vault vault_unsafe_;
 
   // Sync encryption state that is only modified and accessed from the sync
@@ skipping 27 matching lines @@
   base::Time custom_passphrase_time_;
 
   base::WeakPtrFactory<SyncEncryptionHandlerImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncEncryptionHandlerImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_SYNC_ENCRYPTION_HANDLER_IMPL_H_