Revert of Delete base/prefs and update callers to use components.

components/drive/file_system_core_util.cc

 // Copyright 2015 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 "components/drive/file_system_core_util.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/i18n/icu_string_conversions.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "components/drive/drive.pb.h"
 #include "components/drive/drive_pref_names.h"
 #include "components/drive/job_list.h"
-#include "components/prefs/pref_service.h"
 
 namespace drive {
 namespace util {
 
 namespace {
 
 std::string ReadStringFromGDocFile(const base::FilePath& file_path,
                                    const std::string& key) {
   const int64_t kMaxGDocSize = 4096;
   int64_t file_size = 0;
@@ skipping 95 matching lines @@
 GURL ReadUrlFromGDocFile(const base::FilePath& file_path) {
   return GURL(ReadStringFromGDocFile(file_path, "url"));
 }
 
 std::string ReadResourceIdFromGDocFile(const base::FilePath& file_path) {
   return ReadStringFromGDocFile(file_path, "resource_id");
 }
 
 }  // namespace util
 }  // namespace drive