update_engine: Update to build against libchrome-271506.

BUG=chromium:375032
TEST=`FEATURES=test emerge-$BOARD update_engine`

Change-Id: Ia7be302c12b439ad8aece51c9cbe128086626620
Reviewed-on: https://chromium-review.googlesource.com/201045
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
diff --git a/update_attempter_unittest.cc b/update_attempter_unittest.cc
index 2fdd9f5..e5f66aa 100644
--- a/update_attempter_unittest.cc
+++ b/update_attempter_unittest.cc
@@ -209,7 +209,7 @@
           &test_update_completed_marker, NULL));
   ScopedPathUnlinker completed_marker_unlinker(test_update_completed_marker);
   const base::FilePath marker(test_update_completed_marker);
-  EXPECT_EQ(0, file_util::WriteFile(marker, "", 0));
+  EXPECT_EQ(0, base::WriteFile(marker, "", 0));
   UpdateAttempterUnderTest attempter(&fake_system_state_, &dbus_,
                                      test_update_completed_marker);
   EXPECT_EQ(UPDATE_STATUS_UPDATED_NEED_REBOOT, attempter.status());