Remove unnecessary attempts at memory cleaning

net/base/zap.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 NET_BASE_ZAP_H_
-#define NET_BASE_ZAP_H_
-
-#include <stddef.h>
-
-#include <string>
-
-#include "base/strings/string16.h"
-
-namespace net {
-
-// Zap functions are used to clear sensitive data in RAM to minimize the
-// time that people can access them once they are written to disk.
-
-// Overwrite a buffer  with 0's.
-void ZapBuf(void* buf, size_t buf_len);
-
-// Overwrite a string's internal buffer with 0's.
-void ZapString(std::string* s);
-
-// Overwrite a base::string16's internal buffer with 0's.
-void ZapString(base::string16* s);
-
-}  // namespace net
-
-#endif  // NET_BASE_ZAP_H_