Move ReadFileToString to the base namespace.

chrome/browser/feedback/feedback_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/feedback/feedback_util.h"
 
 #include <sstream>
 #include <string>
 #include <vector>
 
@@ skipping 397 matching lines @@
     return false;
   if (file_util::WriteFile(temp_path.Append(kLogsFilename),
                            logs.c_str(), logs.size()) == -1)
     return false;
   if (!file_util::CreateTemporaryFile(&zip_file))
     return false;
 
   if (!zip::Zip(temp_path, zip_file, false))
     return false;
 
-  if (!file_util::ReadFileToString(zip_file, compressed_logs))
+  if (!base::ReadFileToString(zip_file, compressed_logs))
     return false;
 
   return true;
 }
 
 }  // namespace feedback_util