posix: split linux-specific bits out of sys_info_posix

base/sys_info_openbsd.cc

+// Copyright (c) 2009 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/sys_info.h"
+
+#include "base/logging.h"
+
+namespace base {
+
+int SysInfo::NumberOfProcessors() {
+  int mib[] = { CTL_HW, HW_NCPU };
+  int ncpu;
+  size_t size = sizeof(ncpu);
+  if (sysctl(mib, 2, &ncpu, &size, NULL, 0) == -1) {
+    NOTREACHED();
+    return 1;
+  }
+  return ncpu;
+}
+
+}  // namespace base