sync: remove GetAuthenticatedUsername from ProfileSyncService/SyncBackendHost.

chrome/browser/sync/profile_sync_service.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include <list>
 #include <string>
@@ skipping 301 matching lines @@
   // we have an encrypted data type enabled.
   virtual bool IsPassphraseRequiredForDecryption() const;
 
   sync_api::PassphraseRequiredReason passphrase_required_reason() const {
     return passphrase_required_reason_;
   }
 
   // Returns a user-friendly string form of last synced time (in minutes).
   virtual string16 GetLastSyncedTimeString() const;
 
-  // Returns the authenticated username of the sync user, or empty if none
-  // exists. It will only exist if the authentication service provider (e.g
-  // GAIA) has confirmed the username is authentic.
-  virtual string16 GetAuthenticatedUsername() const;
-
   const std::string& last_attempted_user_email() const {
     return last_attempted_user_email_;
   }
 
   // The profile we are syncing for.
   Profile* profile() const { return profile_; }
 
   // Adds/removes an observer. ProfileSyncService does not take ownership of
   // the observer.
   virtual void AddObserver(Observer* observer);
@@ skipping 376 matching lines @@
   FailedDatatypesHandler failed_datatypes_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(
     const browser_sync::SyncProtocolError& error);
 
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_