Move WriteFile and WriteFileDescriptor from file_util to base namespace.

cloud_print/service/win/cloud_print_service.cc

Index: cloud_print/service/win/cloud_print_service.cc
diff --git a/cloud_print/service/win/cloud_print_service.cc b/cloud_print/service/win/cloud_print_service.cc
index e0998f0cf08463c7e7094da6ca98e306f64024f6..6f580951584057c1a475264446ca7ac0bd05d808 100644
--- a/cloud_print/service/win/cloud_print_service.cc
+++ b/cloud_print/service/win/cloud_print_service.cc
@@ -351,7 +351,7 @@ class CloudPrintServiceModule
     }
 
     if (new_contents != contents) {
-      size_t  written = file_util::WriteFile(file, new_contents.c_str(),
+      size_t  written = base::WriteFile(file, new_contents.c_str(),
                                               new_contents.size());
       if (written != new_contents.size()) {
         return ReportError(cloud_print::GetLastHResult(),