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/hwid_override_unittest.cc b/hwid_override_unittest.cc
index 10f23ee..5c654b4 100644
--- a/hwid_override_unittest.cc
+++ b/hwid_override_unittest.cc
@@ -34,16 +34,16 @@
   std::string expected_hwid("expected");
   std::string keyval(HwidOverride::kHwidOverrideKey);
   keyval += ("=" + expected_hwid);
-  ASSERT_EQ(file_util::WriteFile(tempdir_.path().Append("etc/lsb-release"),
-                                 keyval.c_str(), keyval.length()),
+  ASSERT_EQ(base::WriteFile(tempdir_.path().Append("etc/lsb-release"),
+                            keyval.c_str(), keyval.length()),
             keyval.length());
   EXPECT_EQ(expected_hwid, HwidOverride::Read(tempdir_.path()));
 }
 
 TEST_F(HwidOverrideTest, ReadNothing) {
   std::string keyval("SOMETHING_ELSE=UNINTERESTING");
-  ASSERT_EQ(file_util::WriteFile(tempdir_.path().Append("etc/lsb-release"),
-                                 keyval.c_str(), keyval.length()),
+  ASSERT_EQ(base::WriteFile(tempdir_.path().Append("etc/lsb-release"),
+                            keyval.c_str(), keyval.length()),
             keyval.length());
   EXPECT_EQ(std::string(), HwidOverride::Read(tempdir_.path()));
 }