Move WriteFile and WriteFileDescriptor from file_util to base namespace.

courgette/ensemble_apply.cc

Index: courgette/ensemble_apply.cc
diff --git a/courgette/ensemble_apply.cc b/courgette/ensemble_apply.cc
index be3618bc24a6707f8fa594fb7e86fa03f5ba3a9f..967b4e48f5d1c88af15bdc437e4e394bf7255af0 100644
--- a/courgette/ensemble_apply.cc
+++ b/courgette/ensemble_apply.cc
@@ -416,7 +416,7 @@ Status ApplyEnsemblePatch(const base::FilePath::CharType* old_file_name,
   // Write the patched data to |new_file_name|.
   base::FilePath new_file_path(new_file_name);
   int written =
-      file_util::WriteFile(
+      base::WriteFile(
           new_file_path,
           reinterpret_cast<const char*>(new_sink_stream.Buffer()),
           static_cast<int>(new_sink_stream.Length()));