Move ReadFileToString to the base namespace.

chrome/browser/chromeos/policy/user_policy_disk_cache.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/chromeos/policy/user_policy_disk_cache.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 55 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   em::CachedCloudPolicyResponse cached_response;
   if (!base::PathExists(backing_file_path_)) {
     LoadDone(LOAD_RESULT_NOT_FOUND, cached_response);
     return;
   }
 
   // Read the protobuf from the file.
   std::string data;
-  if (!file_util::ReadFileToString(backing_file_path_, &data)) {
+  if (!base::ReadFileToString(backing_file_path_, &data)) {
     LOG(WARNING) << "Failed to read policy data from "
                  << backing_file_path_.value();
     LoadDone(LOAD_RESULT_READ_ERROR, cached_response);
     return;
   }
 
   // Decode it.
   if (!cached_response.ParseFromArray(data.c_str(), data.size())) {
     LOG(WARNING) << "Failed to parse policy data read from "
                  << backing_file_path_.value();
@@ skipping 53 matching lines @@
   int size = data.size();
   if (file_util::WriteFile(backing_file_path_, data.c_str(), size) != size) {
     LOG(WARNING) << "Failed to write " << backing_file_path_.value();
     SampleUMA(kMetricPolicyStoreFailed);
     return;
   }
   SampleUMA(kMetricPolicyStoreSucceeded);
 }
 
 }  // namespace policy