Move ReadFileToString to the base namespace.

chrome/browser/extensions/api/music_manager_private/device_id_linux.cc

 // Copyright 2013 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/extensions/api/music_manager_private/device_id.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace {
 
 const char kDBusFilename[] = "/var/lib/dbus/machine-id";
 
 void GetDBusMachineId(const extensions::api::DeviceId::IdCallback& callback) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
 
   std::string result;
-  if (!file_util::ReadFileToString(base::FilePath(kDBusFilename), &result)) {
+  if (!base::ReadFileToString(base::FilePath(kDBusFilename), &result)) {
     DLOG(WARNING) << "Error reading dbus machine id file.";
     result = "";
   }
 
   content::BrowserThread::PostTask(
       content::BrowserThread::UI,
       FROM_HERE,
       base::Bind(callback, result));
 }
 
 }
 
 namespace extensions {
 namespace api {
 
 // Linux: Use the content of the "DBus" machine-id file.
 /* static */
 void DeviceId::GetMachineId(const IdCallback& callback) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   content::BrowserThread::PostTask(
       content::BrowserThread::FILE,
       FROM_HERE,
       base::Bind(GetDBusMachineId, callback));
 }
 
 }  // namespace api
 }  // namespace extensions