diff --git a/src/net/base/file_stream_whence.h b/src/net/base/file_stream_whence.h
new file mode 100644
index 0000000..a962341
--- /dev/null
+++ b/src/net/base/file_stream_whence.h
@@ -0,0 +1,20 @@
+// 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.
+
+#ifndef NET_BASE_FILE_STREAM_WHENCE_H_
+#define NET_BASE_FILE_STREAM_WHENCE_H_
+
+namespace net {
+
+// TODO(darin): Move this to a more generic location.
+// This explicit mapping matches both FILE_ on Windows and SEEK_ on Linux.
+enum Whence {
+  FROM_BEGIN   = 0,
+  FROM_CURRENT = 1,
+  FROM_END     = 2
+};
+
+}  // namespace net
+
+#endif  // NET_BASE_FILE_STREAM_WHENCE_H_