Move ReadFileToString to the base namespace.

printing/backend/print_backend_cups.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 "printing/backend/print_backend.h"
 
 #include "build/build_config.h"
 
 #include <dlfcn.h>
 #include <errno.h>
@@ skipping 233 matching lines @@
 
   base::FilePath ppd_path(GetPPD(printer_name.c_str()));
   // In some cases CUPS failed to get ppd file.
   if (ppd_path.empty()) {
     LOG(ERROR) << "CUPS: Failed to get PPD"
                << ", printer name: " << printer_name;
     return false;
   }
 
   std::string content;
-  bool res = file_util::ReadFileToString(ppd_path, &content);
+  bool res = base::ReadFileToString(ppd_path, &content);
 
   base::DeleteFile(ppd_path, false);
 
   if (res) {
     printer_info->printer_capabilities.swap(content);
     printer_info->caps_mime_type = "application/pagemaker";
     // In CUPS, printer defaults is a part of PPD file. Nothing to upload here.
     printer_info->printer_defaults.clear();
     printer_info->defaults_mime_type.clear();
   }
@@ skipping 112 matching lines @@
                    << ", HTTP error: " << http_error;
         base::DeleteFile(ppd_path, false);
         ppd_path.clear();
       }
     }
   }
   return ppd_path;
 }
 
 }  // namespace printing