Delete base/prefs and update callers to use components.

ios/chrome/browser/data_reduction_proxy/ios_chrome_data_reduction_proxy_io_data.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 "ios/chrome/browser/data_reduction_proxy/ios_chrome_data_reduction_proxy_io_data.h"
 
-#include "base/prefs/pref_service.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_experiments_stats.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
+#include "components/prefs/pref_service.h"
 #include "ios/chrome/browser/data_reduction_proxy/ios_chrome_data_reduction_proxy_settings.h"
 #include "ios/chrome/browser/pref_names.h"
 #include "ios/web/public/web_client.h"
 
 using data_reduction_proxy::DataReductionProxyParams;
 
 scoped_ptr<data_reduction_proxy::DataReductionProxyIOData>
 CreateIOSChromeDataReductionProxyIOData(
     net::NetLog* net_log,
     PrefService* prefs,
@@ skipping 18 matching lines @@
           new data_reduction_proxy::DataReductionProxyIOData(
               IOSChromeDataReductionProxySettings::GetClient(), flags, net_log,
               io_task_runner, ui_task_runner, enabled, enable_quic,
               web::GetWebClient()->GetUserAgent(false)));
   data_reduction_proxy_io_data->experiments_stats()->InitializeOnUIThread(
       data_reduction_proxy::DataReductionProxyConfigRetrievalParams::Create(
           prefs));
 
   return data_reduction_proxy_io_data;
 }