Move WriteFile and WriteFileDescriptor from file_util to base namespace.

chrome/common/net/url_fixer_upper_unittest.cc

Index: chrome/common/net/url_fixer_upper_unittest.cc
diff --git a/chrome/common/net/url_fixer_upper_unittest.cc b/chrome/common/net/url_fixer_upper_unittest.cc
index 46d41c6e651383355fcaaeac14194e3022fbaf86..a6d4ccecb40a16d6c8974ba4d0127f145325aa42 100644
--- a/chrome/common/net/url_fixer_upper_unittest.cc
+++ b/chrome/common/net/url_fixer_upper_unittest.cc
@@ -225,7 +225,7 @@ static bool MakeTempFile(const base::FilePath& dir,
                          const base::FilePath& file_name,
                          base::FilePath* full_path) {
   *full_path = dir.Append(file_name);
-  return file_util::WriteFile(*full_path, "", 0) == 0;
+  return base::WriteFile(*full_path, "", 0) == 0;
 }
 
 // Returns true if the given URL is a file: URL that matches the given file