Linux: remove unmaintained SELinux code.

sandbox/linux/services/libc_urandom_override.cc

 // 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.
 
 #include "sandbox/linux/services/libc_urandom_override.h"
 
 #include <dlfcn.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/rand_util.h"
 
 // Note: this file is used by the zygote and nacl_helper.
 
 namespace sandbox {
 
-// With SELinux we can carve out a precise sandbox, so we don't have to play
-// with intercepting libc calls.
-#if !defined(CHROMIUM_SELINUX)
-
 static bool g_override_urandom = false;
 
 void InitLibcUrandomOverrides() {
   // Make sure /dev/urandom is open.
   base::GetUrandomFD();
   g_override_urandom = true;
 }
 
 // TODO(sergeyu): Currently this code doesn't work properly under ASAN
 // - it crashes content_unittests. Make sure it works properly and
@@ skipping 120 matching lines @@
   } else {
     CHECK_EQ(0, pthread_once(&g_libc_file_io_funcs_guard,
                              InitLibcFileIOFunctions));
     CHECK(g_libc_xstat64);
     return g_libc_xstat64(version, path, buf);
   }
 }
 
 #endif  // !ADDRESS_SANITIZER
 
-#endif  // !CHROMIUM_SELINUX
-
 }  // namespace content