Move WriteFile and WriteFileDescriptor from file_util to base namespace.

chrome/browser/chromeos/boot_times_loader.cc

Index: chrome/browser/chromeos/boot_times_loader.cc
diff --git a/chrome/browser/chromeos/boot_times_loader.cc b/chrome/browser/chromeos/boot_times_loader.cc
index 451c6a026ef0efc9544b1c2a6de0b02f860d0f3b..6d3c820fdd1f42b6cef438bba2baf7fd8bfe0dcc 100644
--- a/chrome/browser/chromeos/boot_times_loader.cc
+++ b/chrome/browser/chromeos/boot_times_loader.cc
@@ -209,8 +209,7 @@ void BootTimesLoader::WriteTimes(
   }
   output += '\n';
 
-  file_util::WriteFile(
-      log_path.Append(base_name), output.data(), output.size());
+  base::WriteFile(log_path.Append(base_name), output.data(), output.size());
 }
 
 void BootTimesLoader::LoginDone() {