chore: import upstream snapshot with attribution

test/test_file_util_linux.cc

@@ -0,0 +1,26 @@
+// 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.
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "butil/files/file_path.h"
+#include "butil/files/scoped_file.h"
+
+namespace butil {
+
+bool EvictFileFromSystemCache(const FilePath& file) {
+  ScopedFD fd(open(file.value().c_str(), O_RDONLY));
+  if (!fd.is_valid())
+    return false;
+  if (fdatasync(fd.get()) != 0)
+    return false;
+  if (posix_fadvise(fd.get(), 0, 0, POSIX_FADV_DONTNEED) != 0)
+    return false;
+  return true;
+}
+
+}  // namespace butil