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

components/data_reduction_proxy/core/browser/data_reduction_proxy_experiments_stats_unittest.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/data_reduction_proxy/core/browser/data_reduction_proxy_experiments_stats.h"
 
 #include <stdint.h>
 #include <map>
 #include <utility>
 
 #include "base/metrics/field_trial.h"
+#include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/test/histogram_tester.h"
 #include "base/time/time.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config_retrieval_params.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_pref_names.h"
-#include "components/prefs/pref_service.h"
 #include "components/variations/variations_associated_data.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 // Test value for how long a Data Reduction Proxy configuration should be valid.
 const int64_t kConfigExpirationSeconds = 60 * 60 * 24;
 
 }  // namespace
 
@@ skipping 127 matching lines @@
           "DataReductionProxy.ConfigFetchLostBytesDiff_0", 0);
     } else {
       histogram_tester.ExpectUniqueSample(
           "DataReductionProxy.ConfigFetchLostBytesDiff_0",
           test_case.expected_diff, 1);
     }
   }
 }
 
 }  // namespace data_reduction_proxy