Move ReadFileToString to the base namespace.

net/dns/dns_hosts.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 "net/dns/dns_hosts.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
@@ skipping 140 matching lines @@
     return false;
 
   UMA_HISTOGRAM_COUNTS("AsyncDNS.HostsSize", size);
 
   // Reject HOSTS files larger than |kMaxHostsSize| bytes.
   const int64 kMaxHostsSize = 1 << 25;  // 32MB
   if (size > kMaxHostsSize)
     return false;
 
   std::string contents;
-  if (!file_util::ReadFileToString(path, &contents))
+  if (!base::ReadFileToString(path, &contents))
     return false;
 
   ParseHosts(contents, dns_hosts);
   return true;
 }
 
 }  // namespace net