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

components/metrics/clean_exit_beacon.cc

 // Copyright 2014 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/metrics/clean_exit_beacon.h"
 
 #include "base/logging.h"
+#include "base/prefs/pref_service.h"
 #include "build/build_config.h"
 #include "components/metrics/metrics_pref_names.h"
-#include "components/prefs/pref_service.h"
 
 #if defined(OS_WIN)
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/registry.h"
 #endif
 
 namespace metrics {
 
 CleanExitBeacon::CleanExitBeacon(const base::string16& backup_registry_key,
@@ skipping 50 matching lines @@
                     backup_registry_key_.c_str(),
                     KEY_ALL_ACCESS) == ERROR_SUCCESS) {
     regkey.WriteValue(
         base::ASCIIToUTF16(prefs::kStabilityExitedCleanly).c_str(),
         value ? 1u : 0u);
   }
 #endif
 }
 
 }  // namespace metrics