Upstream android file related code.

base/os_compat_android.h

+// 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.
+
+#ifndef BASE_OS_COMPAT_ANDROID_H_
+#define BASE_OS_COMPAT_ANDROID_H_
+#pragma once
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <utime.h>
+
+// Not implemented in Bionic. See platform_file_android.cc.
+extern "C" int futimes(int fd, const struct timeval tv[2]);
+
+// The prototype of mkdtemp is missing.
+extern "C" char* mkdtemp(char* path);
+
+// The lockf() function is not available on Android; we translate to flock().
+#define F_LOCK LOCK_EX
+#define F_ULOCK LOCK_UN
+inline int lockf(int fd, int cmd, off_t ignored_len) {
+  return flock(fd, cmd);
+}
+
+#endif  // BASE_OS_COMPAT_ANDROID_H_