Consistently use base::OpenFile.

Change-Id: Ib9275182c984084f1d4f7e63faf380888b3c0a76
diff --git a/src/base/unix_socket_unittest.cc b/src/base/unix_socket_unittest.cc
index 382f9bc..887b9ec 100644
--- a/src/base/unix_socket_unittest.cc
+++ b/src/base/unix_socket_unittest.cc
@@ -200,8 +200,8 @@
   ASSERT_TRUE(srv_conn);
   ASSERT_TRUE(cli->is_connected());
 
-  ScopedFile null_fd(open("/dev/null", O_RDONLY));
-  ScopedFile zero_fd(open("/dev/zero", O_RDONLY));
+  ScopedFile null_fd(base::OpenFile("/dev/null", O_RDONLY));
+  ScopedFile zero_fd(base::OpenFile("/dev/zero", O_RDONLY));
 
   auto cli_did_recv = task_runner_.CreateCheckpoint("cli_did_recv");
   EXPECT_CALL(event_listener_, OnDataAvailable(cli.get()))