Move dir_reader to base/files
TEST=it compiles
BUG=none
Review URL: https://chromiumcodereview.appspot.com/10413022
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144989 0039d316-1c4b-4281-b951-d872f2087c98
CrOS-Libchrome-Original-Commit: d88e17fa4882a14b86ac753780f20d9481d7d113
diff --git a/base/files/dir_reader_posix.h b/base/files/dir_reader_posix.h
new file mode 100644
index 0000000..9d77d47
--- /dev/null
+++ b/base/files/dir_reader_posix.h
@@ -0,0 +1,37 @@
+// 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 BASE_FILES_DIR_READER_POSIX_H_
+#define BASE_FILES_DIR_READER_POSIX_H_
+#pragma once
+
+#include "build/build_config.h"
+
+// This header provides a class, DirReaderPosix, which allows one to open and
+// read from directories without allocating memory. For the interface, see
+// the generic fallback in dir_reader_fallback.h.
+
+// Mac note: OS X has getdirentries, but it only works if we restrict Chrome to
+// 32-bit inodes. There is a getdirentries64 syscall in 10.6, but it's not
+// wrapped and the direct syscall interface is unstable. Using an unstable API
+// seems worse than falling back to enumerating all file descriptors so we will
+// probably never implement this on the Mac.
+
+#if defined(OS_LINUX)
+#include "base/files/dir_reader_linux.h"
+#else
+#include "base/files/dir_reader_fallback.h"
+#endif
+
+namespace base {
+
+#if defined(OS_LINUX)
+typedef DirReaderLinux DirReaderPosix;
+#else
+typedef DirReaderFallback DirReaderPosix;
+#endif
+
+} // namespace base
+
+#endif // BASE_FILES_DIR_READER_POSIX_H_