Move WriteFile and WriteFileDescriptor from file_util to base namespace.

chrome/browser/media/webrtc_log_uploader.cc

Index: chrome/browser/media/webrtc_log_uploader.cc
diff --git a/chrome/browser/media/webrtc_log_uploader.cc b/chrome/browser/media/webrtc_log_uploader.cc
index 8752cb373a9b7b70b4242bc8e9faf7f047f38489..1551e788c83236e978019ed6565f81cf7482d1f3 100644
--- a/chrome/browser/media/webrtc_log_uploader.cc
+++ b/chrome/browser/media/webrtc_log_uploader.cc
@@ -302,8 +302,8 @@ void WebRtcLogUploader::AddUploadedLogInfoToUploadListFile(
   contents += base::DoubleToString(time_now.ToDoubleT()) +
               "," + report_id + '\n';
 
-  int written = file_util::WriteFile(upload_list_path, &contents[0],
-                                     contents.size());
+  int written =
+      base::WriteFile(upload_list_path, &contents[0], contents.size());
   DPCHECK(written == static_cast<int>(contents.size()));
 }