Revert of Implement ScopedFD in terms of ScopedGeneric.

base/files/scoped_file.cc

-// Copyright 2014 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.
-
-#include "base/files/scoped_file.h"
-
-#include "base/logging.h"
-
-#if defined(OS_POSIX)
-#include <unistd.h>
-
-#include "base/posix/eintr_wrapper.h"
-#endif
-
-namespace base {
-namespace internal {
-
-#if defined(OS_POSIX)
-
-// static
-void ScopedFDCloseTraits::Free(int fd) {
-  // It's important to crash here.
-  // There are security implications to not closing a file descriptor
-  // properly. As file descriptors are "capabilities", keeping them open
-  // would make the current process keep access to a resource. Much of
-  // Chrome relies on being able to "drop" such access.
-  // It's especially problematic on Linux with the setuid sandbox, where
-  // a single open directory would bypass the entire security model.
-  PCHECK(0 == IGNORE_EINTR(close(fd)));
-}
-
-#endif  // OS_POSIX
-
-}  // namespace internal
-}  // namespace base