Remove AsyncSetOwnerUser() from cryptohome library

chrome/browser/chromeos/cros/cryptohome_library.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_CHROMEOS_CROS_CRYPTOHOME_LIBRARY_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_CRYPTOHOME_LIBRARY_H_
 #pragma once
 
 #include <string>
 
@@ skipping 57 matching lines @@
   virtual bool AsyncMountForBwsi(Delegate* callback) = 0;
 
   // Asks cryptohomed to asynchronously try to find the cryptohome for
   // |user_email| and then nuke it.
   virtual bool AsyncRemove(const std::string& user_email,
                            Delegate* callback) = 0;
 
   // Asks cryptohomed if a drive is currently mounted.
   virtual bool IsMounted() = 0;
 
-  // Passes cryptohomed the owner user. It is used to prevent
-  // deletion of the owner in low disk space cleanup (see above).
-  virtual bool AsyncSetOwnerUser(const std::string& username,
-                                 Delegate* callback) = 0;
-
   // Wrappers of the functions for working with Tpm.
 
   // Returns whether Tpm is ready.
   virtual bool TpmIsReady() = 0;
 
   // Returns whether Tpm is presented and enabled.
   virtual bool TpmIsEnabled() = 0;
 
   // Returns whether device has already been owned.
   virtual bool TpmIsOwned() = 0;
@@ skipping 39 matching lines @@
   virtual std::string GetSystemSalt() = 0;
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via CrosLibrary::Get().
   static CryptohomeLibrary* GetImpl(bool stub);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_CRYPTOHOME_LIBRARY_H_