Remove unused fields found by clang's new Wunused-private-fields.

chrome/browser/mock_browsing_data_file_system_helper.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_MOCK_BROWSING_DATA_FILE_SYSTEM_HELPER_H_
 #define CHROME_BROWSER_MOCK_BROWSING_DATA_FILE_SYSTEM_HELPER_H_
 #pragma once
 
 #include <list>
 #include <map>
@@ skipping 30 matching lines @@
 
   // Returns true if all filesystemss since the last Reset() invocation were
   // deleted.
   bool AllDeleted();
 
   GURL last_deleted_origin_;
 
  private:
   virtual ~MockBrowsingDataFileSystemHelper();
 
-  Profile* profile_;
-
   base::Callback<void(const std::list<FileSystemInfo>&)> callback_;
 
   // Stores which filesystems exist.
   std::map<const std::string, bool> file_systems_;
 
   std::list<FileSystemInfo> response_;
 };
 
 #endif  // CHROME_BROWSER_MOCK_BROWSING_DATA_FILE_SYSTEM_HELPER_H_